I rode some sections today on the Fatbike and the conditions were perfect for it.
Loop 1 was pretty packed down from hikers and skiers.
Loop 4 saw a lot less traffic and was a little harder going. At the end of the loop near the RR tracks there were 4 or 5 trees down all in one spot. No way to crawl over and very difficult to get around because of vines and thorns.