Transport from Heathrow on Christmas Day
 

With public transportation not operating on Christmas day, how does one travel from Heathrow to hotel located near Swiss Cottage?

Two companies to try: London-Transfers.com ( I've used this one myself many times and highly recommend it) or JustAirports.com

Good luck!

The Heathrow Express / Heathrow Connect train service will run on Xmas Day, though it will probably be a replacement bus service.
Details will be posted on the web sites nearer the time.
Paddington the London terminus is about a mile by taxi.

Also the Dot2Dot hotel shuttle bus will also be running Xmas Day

I'd go with the car service as you aren't at a hotel convenient for Paddington so you'd need to find a taxi to take you the rest of the way

Thanks for the suggestions!