Cheaper than alternatives (depression, moto racing, or illicit things). Easier on the body than ultra running.
One more option would be 4iiii fliiiight trainer. It can run for more than 2 hours from internal battery power. Since it’s charged via USB-C you could also power/charge it from a portable USB battery pack. It’s also quite light and can fit into a small space.
I’ve successfully run my KIckr 17 off a 12 volt gel cell battery. The power consumption is surprisingly low. My main problem is trying to source a barrel connector that is compatible with the Kickr. For the test, I cobbled it together and held it with electrical tape. I’m looking to set it up so I can use it with the 12 volt system in our RV. Gotta keep up with the schedule.
Would love to take the kickr but the heliport would laugh at me and politely tell me to bugger off if I tried to check that much weight onto a helicopter.
If you want to go real light, I recommend the Fastback roller system with the front fork mount. It’s a dumb trainer, but with a power meter on the bike, you can do all of your workouts unless you’re extremely powerful. I often travel for work, and have borrowed this. Good Luck.
Tom
My mistake, I meant Feedback Sports Omnium Rollers.