How to get terminal back after I suspend a computer over SSH?

Solution 1:

Enter SSH escape codes! From man ssh:

ESCAPE CHARACTERS
 When a pseudo-terminal has been requested, ssh supports a number of
 functions through the use of an escape character.

 A single tilde character can be sent as ~~ or by following the tilde by a
 character other than those described below.  The escape character must
 always follow a newline to be interpreted as special.  The escape
 character can be changed in configuration files using the EscapeChar
 configuration directive or on the command line by the -e option.

 The supported escapes (assuming the default ‘~’) are:

 ~.      Disconnect.

 ~^Z     Background ssh.

 ~&      Background ssh at logout when waiting for forwarded connection /
         X11 sessions to terminate.

So: press Enter~..