Maybe I used the term "thermal envelope" too loosely? I agree that restoring an air seal is trivial on a per-hole basis. My main point was restoring the lost i

Maybe I used the term "thermal envelope" too loosely? I agree that restoring an air seal is trivial on a per-hole basis. My main point was restoring the lost insulation performance that comes from trashing one stud cavity of fiberglass batt insulation when the hole is made. Based on my limited knowledge, I don't know what impact that might have on the overall structure's thermal efficiency. I would also worry about risk to any water-carrying pipes running through such a section in a cold climate.