Place text after dots inline with the second line of text overflow ellipsis

In the future you will be able to do this with only one line of code using:

line-clamp: 2 "...123 T.";

You can find more detail in the specification:

The line-clamp property is a shorthand for the max-lines, block-ellipsis, and continue properties.

It allows limiting the contents of a block container to the specified number of lines; remaining content is fragmented away and neither rendered nor measured. Optionally, it also allows inserting content into the last line box to indicate the continuity of truncated/interrupted content.

enter image description here

Until then, here is a very hacky idea to achieve the result:

.container {
  max-width: 200px;
  margin: 5px;
}

.main-text {
  line-height: 1.2em; /* the height of a line */
  max-height: calc(2 * 1.2em); /* restrict the height to 2 lines*/
  overflow: hidden;
  display: inline-block;
  position: relative;
}

.main-text:after {
  content: "123 T.";
  display:inline-block;
  width:40px;
  position:relative;
  z-index:999;
  /* a big box-shadow to hide the span element used for the ellipsis */
  box-shadow:
    40px 0 0 #fff,
    80px 0 0 #fff,
    120px 0 0 #fff,
    160px 0 0 #fff;
  /**/
  color: #8e8f8f;
  font-size: 10px;
  background: #fff; /* white background to cover the text behind */
  margin-left:2px;
}

/* this will replace the ellipsis */
.main-text span {
  position: absolute;
  /* position at the bottom right */
  top: 1.2em; /* height of one line */
  right: 0;
  padding: 0 3px;
  background: #fff; /* white background to cover the text behind */
}

.main-text span:before {
  content: "..."; /* the dots*/
}

/* the text after the dots */
.main-text span:after {
  content: "123 T.";
  color: #8e8f8f;
  font-size: 10px;
<div class="container">
  <div class="main-text">
    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam metus mi, dapibus sit amet posuere eu, porttitor condimentum nulla. Donec convallis lorem justo, eget malesuada lorem tempor vitae. Aliquam sollicitudin lacus ipsum, at tincidunt ante condimentum
    vitae. <span></span>
  </div>
</div>

<div class="container">
  <div class="main-text">
    Lorem ipsum <span></span>
  </div>
</div>

<div class="container">
  <div class="main-text">
    Lo <span></span>
  </div>
</div>

<div class="container">
  <div class="main-text">
    Lorem ipsum dolor sit ameta, adipiscing elit. Nam metus <span></span>
  </div>
</div>

<div class="container">
  <div class="main-text">
    Lorem ipsum dolor sit ameta, adipiscing elit <span></span>
  </div>
</div>

Or like below if you want the text to appear only with the dots:

.container {
  max-width: 200px;
  margin: 5px;
}

.main-text {
  line-height: 1.2em; /* the height of a line */
  max-height: calc(2 * 1.2em); /* restrict the height to 2 lines*/
  overflow: hidden;
  display: inline-block;
  position: relative;
}

.main-text:after {
  content: "."; /* at least one character to set the height */
  display:inline-block;
  width:40px;
  position:relative;
  z-index:999;
  /* a big box-shadow to hide the span element used for the ellipsis */
  box-shadow:
    40px 0 0 #fff,
    80px 0 0 #fff,
    120px 0 0 #fff,
    160px 0 0 #fff;
  /**/
  color: transparent; /* no colorataion*/
  font-size: 10px;
  background: #fff; /* white background to cover the text behind */
  margin-left:2px;
}

/* this will replace the ellipsis */
.main-text span {
  position: absolute;
  /* position at the bottom right */
  top: 1.2em; /* height of one line */
  right: 0;
  padding: 0 3px;
  background: #fff; /* white background to cover the text behind */
}

.main-text span:before {
  content: "..."; /* the dots*/
}

/* the text after the dots */
.main-text span:after {
  content: "123 T.";
  color: #8e8f8f;
  font-size: 10px;
<div class="container">
  <div class="main-text">
    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam metus mi, dapibus sit amet posuere eu, porttitor condimentum nulla. Donec convallis lorem justo, eget malesuada lorem tempor vitae. Aliquam sollicitudin lacus ipsum, at tincidunt ante condimentum
    vitae. <span></span>
  </div>
</div>

<div class="container">
  <div class="main-text">
    Lorem ipsum <span></span>
  </div>
</div>

<div class="container">
  <div class="main-text">
    Lo <span></span>
  </div>
</div>

<div class="container">
  <div class="main-text">
    Lorem ipsum dolor sit ameta, adipiscing elit. Nam metus <span></span>
  </div>
</div>

<div class="container">
  <div class="main-text">
    Lorem ipsum dolor sit ameta, adipiscing elit <span></span>
  </div>
</div>

Does the following code give the desired output?

.outside-container {
  width: 220px;
}

.container {
  width: 100%;
  margin-bottom: 20px;
  display: flex;
  align-items: flex-end;
}

.main-text {
  overflow: hidden;  
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  margin-right: 5px;
}

.small-text {
  color: #8e8f8f;
  font-size: 10px;
  white-space: nowrap;
  transform: translateY(-2px);
}
<div class="outside-container">
  <div class="container">
    <span class="main-text">
          Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam metus mi,
          dapibus sit amet posuere eu, porttitor condimentum nulla. Donec
          convallis lorem justo, eget malesuada lorem tempor vitae. Aliquam
          sollicitudin lacus ipsum, at tincidunt ante condimentum vitae.
        </span>
    <span class="small-text">123 T.</span>
  </div>
  <div class="container">
    <span class="main-text">
          Lorem ipsum
        </span>
    <span class="small-text">123 T.</span>
  </div>
  <div class="container">
    <span class="main-text">
          Lorem ipsum dolor sit ameta,  adipiscing elit. Nam metus  Donec
          convallis lorem justo, eget malesuada lorem tempor vitae. Aliqua
        </span>
    <span class="small-text">123 T.</span>
  </div>
</div>