Are your 33's terrible in the snow because they're too wide, or because the treads aren't any good? I suspect someone will tell you soon that if you sipe BFG Mud's they grip better. IMO, on a 40 it's better to go with a narrower tire, since those cute little 40's don't weigh very much the tires go deeper into the snow and grab better. I really like the 33 9.50's, which would give you a similar setup to what Ken Romer has, that's what I'd run if I had a 40..
And afaik you could still run 35's and not be sprung over, Scott Brown did that with some sort of revolver shackles, and a shackle reversal on his yellow 40. Not sure what springs he had but I could ask next time I see him if it's important. Just don't get Pinnacles, right Ige?
82 fj40, 99 uzj100, 06 gx470
97 DR650, 05 525EXC, 01 XT225, 09 TTR125, 07 TTR90, 07 CRF50