Haha unfortunately parking up hill wont work. If the battery is dead on a Strom, you're screwed. Bump starting is not an option. One of a very short list of things I don't like about the Strom 650.
I figure at this point I'll throw it in if I have the time to do so before we take off. If I don't have time then o well. My girl has never been able to charge her camera while on the road before, so this will not be any different. I do know that if I do hook one up, it will be wired to the "switched" circuit of the fuse box.
I figure I'll just wire in a 12V accessory "cigarette lighter" under the seat, and plug the inverter into it.