Newbie: Winter Wisconsin camping without Polar/Arctic/etc

I guess what I'm looking for is:
1) are there any serious flaws in my plan (such as fire hazard with straw skirt, thanks for pointing it out)
2) am I at risk of hurting the TT

I know it won't be fancy, but it'll be somewhat heated, dry, and out of wind. The TT should be better than a tent by far.

Thanks for pointer on blowing out unit. Seems pretty doable.