Front and rear suspension in 120mm to 140mm travel, 1x12 drivetrain, and a dropper would be my standards. Something like that Stumpy or a Fuel Ex would be great choices.
I have a Fuel Ex8 29nr and really like it but there are a number of good bikes in that category
I would assume you would be breaking fresh tracks. The last 10 or 20 miles was down to just 2 tracks thru there woods, one vehicle wide. It's a really pretty drive in the summer but I doubt it gets driven in the winter. I'm sure if you wanted to run the route you could bypass wherever there's no...
That's not really winter in northern Wisconsin. I would have to say that's probably late fall. We have between 12"-18"of snow right now and up close to the lake probably more. I ran the trail 2 years ago and there would be quite a bit of the very northern part that wouldn't get plowed all winter
I had closed cell foam sprayed under my enclosed trailer that I used for work. I've put around 70,000 miles on it since then in all kinds of weather and it hasn't soaked up any moisture. It would be really hard to do the underside of my van completely that way though, you wouldn't want to cover...
OTC makes a very nice and easy to use automotive crimper. It's copied from a design that both Mac Tools and Snap-on uses that is very popular.