Many Japanese people use this traditional table which is called KOTATSU こたつ in winter.
The table is covered by a thick blanket like in the picture above.
It has a built-in electric heater.
We place our legs under the Kotatsu while sitting on the floor.
Once you sit in Kotatsu, it is hard to exit from it, because it is really comfortable.
I sometimes spent nights lying under the table.
However, it is not a bed, and I realized I had slept all night long in Kotatsu.
I don't recommend to sleep in Kotatsu for long hours, because sleeping long periods in Kotatsu makes our bodies sluggish and tired.
Nevertheless, sleeping in Kotatsu is nice and warm. I can't stop using Kotatsu during winter.
In Japan, many furniture shops sell Kotasu mainly in winter.
A furniture shop in Tokyo:
A bar restaurant in Tokyo:
Honke KANOYA Kagoshima 本家 かのや 鹿児島
(in Japanese) Some of their tables are Kotatsu during winter season.
Why don't you stop by the places?