Yellowstone - Labor Day Weekend 2015

If you are only going to stay in Grand Teton for two days, you will probably be ok without power, as long as you have good battery(Ies) and are frugal with your electrical use. We go up to Grand Teton about three times a year and stay at the Colter Bay Campground(almost all not power) and usually get about five days out of our battery bank before starting to use the generator. There is one loop in the Colter Bay Campground that has power, but it has most of it's spots set aside for folks with special electrical needs. However, you can get a spot later in the day since they usually free them up a little later in the day, after 2 or 3, if I remember correctly. Gros Ventre Campground is another on that has special power places like Colter Bay, but it's further away from Jackson Lake, so not as convenient, in my opinion, to the majority of the Park. There's always a chance of somewhat bad weather, but you just have to be prepared with coats, etc. After all, you are in the mountains in the late summer and it can rain or snow at almost any time. It's also a very beautiful time with the leaves starting to turn and nowhere near as many tourists so crowds are not a problem. Colter Bay RV has full hookups, but in 50 years of going to Colter Bay, we have never not seen a "FULL" sign posted at the entrance of the RV park. However, give them a call and see if you might get a spot, it's still pretty early in the year. Sorry, I don't have a number for them.