Time to bring in the "Draft Hunters"
Caulk, caulk cord, plastic window treatment, insulation, more caulk, spray foam.
This year we'll completely redo the window treatments. Everything will get remeasured and cut to fill. That is the cheepest thing we can do. From experience, after cutting the big drafts; the small drafts become easier to spot.
This thread is going to be a long one.
I'm trying to find a mason to build a chimney. When we moved this house; I poured a footing footprint for a woodstove in the basement. And layed 5 layers of block to the ground level. I need to go about 20 more feet up.