Generally speaking, buckling your boots as tight as possible when not wearing them is a good practice because it allows the boot to mold to a tighter form, thus staying tighter around your foot when wearing them. Leaving them unbuckled can ruin the form of the boot and sometimes even ruin the comfort and shell as well.
I left mine unbuckled for about a month in the summer. When i went to buckle them again for a summer set-up, i damn well knew the difference. since then, i keep them 1 or 2 spots(?) (no idea what to call the notches, maybe i shoulve just called them notches to begin with) tighter than i normally do. keeps them feeling really nice and comfy all the time now.
When you get home try loosely wadding some newspaper up in your liner. Take it out after about an hour then place near the heater. If no heater at least place them somewhere warm lying down so that some sort of draft can get in to them.