Does anyone remember the movie Apollo 13? Specifically that character who was the manufacturing rep for the LEM. As I recall, he has only two scenes - the first to tell the flight director that his company couldn't guarantee performance of the craft when used out of spec; and the second to fist pump the performance of the craft his company produced
Out of spec operations on AC motors are much the same. It might melt, but if it doesn't it can do a lot.
More seriously, AC induction motors are very simple machines. Not so simple as the inclined plane, but they are chunks of iron and copper. Like the other thread about cutting threads, know the math before you experiment too broadly, but unless your duty cycle is continuous, there is quite a lot of leeway
Is it Friday yet?