where 2 get water for RV before you reach your destination?

fill at home:

1) when we get to the campground I then have at least several days before I need to hook up water. No rush to get water hooked up.
2) more than once I've been at a campground where either they had plumbing problems or power problems and no water for anywhere from a few hours to a few days.

worrying about the extra weight is like worring about the weight of an extra bag of groceries in the car. Seriously 50 gallons of water =400 lbs. out of somewhere between 10,000 and 20,000 total pounds. it's insignficant.