The only problem I have with a heavy baselayer is sweating on the way to the stand. Then an hour later im freezing. I havent quite figured out a system to stop this. If I make it 1/4 mile to my tree without sweating, I always sweat getting up the tree.
I sweat way more than average which is why I went with Merino Wool and fleece mid layers. The wool still retains its ability to keep you warm even when wet and it wicks very well. If it's gonna be under 20 degrees for most of my hunt I'll put Under Armour base layers on over the wool and I can sit all day. The wool wicks well enough that if i'm carrying my phone or pistol inside my bib pocket they'll be wet when I take them off after the hunt but I'll be dry and warm the whole hunt.
