Sitting here in the frigid desert of Eastern Washington in a fifth-wheel, I got cold sitting at the table using the computer. Having learned just this morning about a Kotatsu, I was inspired. I have no desire to sit on the floor, so I wasn't going to build the whole thing, just going to work with what I have for a table.
This is what I have.
I placed non-slip material on the table.
Cheap blanket from the local big box store. You know the one, lots of trashy customers, treats their employees badly...
More non-slip material.
The local home improvement depot type place was kind enough to cut this piece of paneling for me. I even have a spare in case I mess one up.
I already had this heater. I just pushed it underneath for the daytime. At night I'll pull it back out to heat the rest of the room.
Laptop back in place.
It stays nice and toasty under here. I may be able to heat it with something much less, will experiment.