I would not ride the same bike for those two trips. If there are water supply issues on a route, I take more bottles. I have taken up to 5, three in jersey pockets.
I'm not a big proponent of bikes like the LHT for distance riding, but it will work. I wouldn't mind having something like the LHT for a commuter, but around here it's a little too nice and would be a theft magnet. I ride crummy but capable bikes on my commute.