I'm not sure about a zillion times
bigger but lots of stars have more mass than our sun does. we've got a medium-small yellow.....which is good news if yr worried about core collapse at some point.
thanks to the redefinition of "planet", I'm not sure that a body much smaller than Mercury would qualify as one any longer.
I firmly believe that life is like a virus and spreads from "planet" to "planet" via ejection material. adaptation depends on the environment, and I'm sure that SOMEWHERE there is a colony of super-small Astral-Sea Monkies plotting universal domination.
that being said....I think there's still a very good chance that life exists in the polar caps of Mars. there's also a decent chance that there is something under the ice of Europa (points to avatar). granted...."life" doesn't mean that it's likely more than single-cell organisms.