I'm in wisconsin and I usually have cams up over winter. previously i've had a moultrie d40 and i40 up, the d40 goes into "sleep" pretty deeply and the batteries seemed to have run out pretty quickly. the i40 has taken good pictures up until about jan/feb, then it starts to slow down a bit (extra amount of empty pics, ect). the batteries in that last quite a while even through the snow.

have a bushnell this year that's been out there since gun season, i have the rechargeable batteries from trailcampro and haven't charged them yet, supposedly they'll last a year so we'll find out this winter!