Two winters ago we had -50 for about a week. Down in the south a lot of deer perished. Whitetail numbers last fall were very low (down 90% in my area).
This winter was better, but I suggest looking central Sask up toward the tree belt. Deer were doing a lot better up there until they got 4' of snow this spring - a friend of mine said the deer were stuck, starving and couldn't even move.
Not sure how much of an impact it made on populiation but down here in the south numbers are low. Haven't seen any fawns yet, but they should be comin' any day!
East Central might be your best bet, but im no expert, just a hick who likes to hunt.