There are a few sources of warmth in this scene. It's a cozy little space, thanks to the CB2 Neville House's proportions. 1:16 or smaller fits best here. I've made use of a Playmobil living room set, which is scaled at 1:18. It is manufactured looking like this:
I had to spray paint something a flat black for a book cover job (yes, I got another one!), so I decided to spray over some of the pieces in this set, specifically, the wood stove, couch, and chair (I left the orange cushions and the cat was black already):

How about the warm glow given off by that fabulous column light by the amazing Pepper of MitchyMoo Miniatures??? She is a genius with minis and a warm person, to boot. Thank you again, Pepper dear!

See the fur teacup on the wall? As an art history major, Meret Oppenheim's creation from 1936 is one of the iconic pieces you learn about in discussion about Surrealism. Fabulous, no?

Of course, a warm pair of boots doesn't hurt!

Happy New Year to all! Stay warm...!

Credits: Couch, chair, wood stove, and cat are all Playmobil; rug is cut felt from Michaels; coffee table is a salt bowl from bodum; light is by Pepper of MitchyMoo Miniatures; wall shelf is Miner. Accessories are Michaels, The Shopping Sherpa, and Manor House Miniatures. 

The time it took me: 47 minutes