Yes/No. Depends on where your Queen came from, originally. Say you buy your queen from, say Fl., which is a common distributor of Queens and "Starter" packs. Well, she (and they) are 'programed' via DNA to live/mate/produce in a certain number of days. Whereas, just the opposite if you acquire a Queen/starter pack from a northern region.
Yes, to the 2nd. They will 'Defend' the hive, come hell or high water...even if it means keeping it warm vs starving to death!