How would it change society if we knew that our entire solar system will be wiped out in a foreseeable future.

In 5 years, in a generarion, this century?
I think most people would draw the line at this millennia.
Historically speaking, the world of our species has always been in a turmoil of great changes with pockets of order and safety.
During the cold war people lived with the fear that everything could come to an end at any time.

Only the ignorant seemed to be unaffected.