shot distance for rifle - bear over bait

[BriBri]

I will be going on a bear-over-bait hunt in May in New Brunswick, and I will be shooting my .270 with 150gr SP Core-Lokts. I am wondering at what distance I should be from the bait pile. I will be in a tree stand (I believe about 20ft up), and I am comfortable shooting off-hand (although there will be a rifle rest) anywhere up to 100 yards. The outfitter has a few options and I was thinking of somewhere in the 50-60 yard range. I want to be close enough to make a perfect shot (as well as be able to size up the bear and make the boar/sow distinction), but I want to be far enough away to not be (visually) spotted or easily winded/heard by the bear. I would appreciate any suggestions on the topic or even people's personal preferences. Thanks.

-Brian