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, 06 TW200, 89 TW200, 09 TTR125, 07 TTR90, 07 CRF50