With the M of the remaining players dropping <10 because of huge blinds you will often find yourself in this situation in late stages of MTTs.
At this point you will often only have two options - shove or fold.
Sometimes you will have to win HU coinflips in order to get to the FT.
As a rule of thumb I look at opponents preflop raising range figuring that their shoving + call ai range in late stages will be close to their initial raising + calling range.
Depending on position and reads (or HEM stats) my preflop shoving range varies here including AQo, AQs, AKo, AKs, 66+.
The strategy section of CC covers this pretty well, too. Try this link => Multi Table Tournament Guide