Boxerworks.com

There is an Airhead I talked with at the Boone, NC Rally this month who had a CPAP machine that ran on 12 volts. He plugged it into his R100RT battery for the night. I think the bike was one of the early 80's RT's...
Anyhow the machine was quite low current drain, and the bike started quickly in the morning.
Keep in mind the R100's can hold a respectable-sized battery. (Mine is a 425 CCA Lawn mower battery. THAT will run a lot of equipment for a while)

Many State Parks have sites with electrical hookups. A possibility if all you possess is a 120v system. Also consider RV parks.

While a shot of Old Grandad sounds attractive, not using one's CPAP is a recipe for health problems due to oxygen deprivation.

These machines are becoming more and more prevalent among US BMW riders. At the BMWMOA International Rally, the guys requesting camping with electrical hookup is growing every year and is currently a significant percentage.

Tires? no. But they will do the majority of the job for air-mattresses, as the hose from the machine happens to be about the right size for the larger inflation-bungholes on lots of modern mattresses.