Get a gravity flow water filter like a Playtypus(sp?) or Sawyer to have safe water without boiling. You can also get purification tablets.
Sure waterfilters are great! I think boiling is easier, than getting another thing, but YMMV.
I don't like the purification tablets, crazy chemical stuff, what kills germs kills people too.
I once tried powerded milk, the most disgusting stuff I ever ate :-! but I might have got the wrong brand. I just avoid milk altogether.
In your shoes, I think I'd buy a DC to AC power converter/inverter and buy (at least) a cheap electric teapot.
So you convert gas to heat, convert that to rotational energy, convert that to 12V, put in a battery, get it out of the battery and convert it to 230V and then convert it to heat? Sounds nice. ;)
Seriously it depends how much hot water you need. If you're firing up your stove for every cup of coffee, a electric tea pot might be better. If you do all cooking and boiling in one session, using the stove is much more effective.
While we're at it: Don't drain your cars battery, turn your car on at least once a week and let it run for at least 20 minutes. Best combined with some driving, better for the engine too.
I like planning for such a trip, guess I should go head out for myself!