It's an annoying problem, cold feet in the comfort of your home.
Here's my solution. Wear some cheap, old, soft, stretchy trackies and wrap the ends around your feet like so:
Seriously though. Works like a charm. You can even walk around like that to keep cold floors at bay.
Parents may moan it's ruining the trackies but that's why you use cheap ones.
Slight problem though. If, like me, you've been doing this for a few years, you may get this slight problem. Baguette.