Can my apartment complex asked EVERYONE to move out w/in 60 days...or else be evicted? help!?

My property management company sent out notices to EVERYONE in our comlex stateing that, a new owner has bought the building and wants everyone to vacate by the end of July, due to reconstruction. They say they will have our security deposit ready for us upon the return of our keys and a $250 incentive (which doesn't cover the cost of moving! w/ uhaul, time spent finding new places, & traveling to look at new apartments) I AM STRESSIN! idk my rights, but i do know that THIS IS A HUGE BURDEN! i have 2 young children, NO EXTRA TIME and NO EXTRA MONEY! (not even for the bus rides to view potential places to live =( ...$250 is NOT worth the stress and trouble of relocating and I DESERVE my deposit back under ANY circumstances! (so i don't really view the deposit i put down as an incentive to move out ASAP, OH and you only get the $250 if you vacate by July 17th!!!.....uhhhhhggggggghhhh! SO STRESSED! WHAT ARE MY RIGHTS?! I know what they are doing LEGAL but surely not MORAL, i may end up on the streets @ the end of it all because Portland has VERY LITTLE OPEN VACENCIES for renters! especially for low income families.