Jim,
The problem is, as you well know-There's snow, and then there's snow. Frankly, on those tires, a couple inches of snow shouldn't be a problem.
But, how are you going to determine snow depth/consistency from the air?
I've landed in light, fluffy interior Alaska snow that was over a foot deep on Bushwheels, but that's the type of snow that blows away when you just breath on it...and it's a type of snow that doesn't happen many places.
If you can get out there on foot BEFORE landing, that's ideal, of course...offers the opportunity to judge snow depth and consistency.
Consistency (crusty/heavy, wet/fluffy, multiple crusts, etc) is almost more important than snow depth. Six inches of new snow on those tires that's not heavy/wet snow might be okay, but six inches of heavy wet stuff, or crusty snow might be less fun.
And, bear in mind, conditions when you land may change while you're on the surface, as temperatures increase.
Definitely land as far back on the tires as you can....nose high at touch, tailwheel first if you can, and stick all the way in your gut. And, be prepared to go full power and leave suddenly, maybe.
My (conservative) policy has always been skis for snow, unless it's really very little snow. Your mileage may vary. I'm guessing you know as much about snow as anyone here, based on where you live.
MTV