We got an estimate today for improving/reinsulating the main attic and the one over the mudroom and kitchen. This person recommended putting in a new vapor barrier (well, the mudroom attic doesn't even have one, the air flow through that space is extreme) and blown in insulation instead of batts, because, he says, mice are happy burrowing in fibreglass, but hate cellulose. Never heard that before.
So by the end of September we should have improved insulation in all attics and the new windows should be in. Yay!