Alternatives of 'a snowball's chance in hell'

I am looking for a different, common English idiom that expresses the same thing as a snowball's chance in hell. My teacher says I use this expression too much, and that it is not appropriate for every essay. I need a same meaning like something very cold in a hot place to have a little chance.

Solution 1:

'You've got two chances--slim and none...and Slim left town'.

Solution 2:

Here are some alternatives you may consider:

• chance in a million

• next to impossible

• poor prospect

• ghost of a chance

Although I do agree these may not come across as colorful enough.

Solution 3:

I like the (eastside)Davy Mac of Ron&Fez radio fames spin on the clasic...

Which went somthing to the effect of, "Im left with Jack and Shit.. Except Jack just left town!"

Note Im not quite sure if it actually fits this particular idioms formula or intention.. Truthfully just wanted to share what I believe to be a lesser-known personal favorite.. So thanks reguradless of relevance..