Cool! I want to do the same for my truck I hope there will be space for my 2 Tommaso https://www.bikethesites.com/road-bikes-under-2000/ they're quite big.
I have a dual fuel generator Champion , it's very powerful, but I also can't recommend doing that even with a potent generator. Don't rush, give the car time to charge, I'm not sure, but it seems to me that using the car while charging can damage the accumulator
Just don't leave it for a long time, otherwise, the engine will be frozen in really cold temperatures. Perhaps you have problems with the alarm system.