Staying in Jackson or Victor will add needless time to your visit to the parks. Jackson is 35 miles from Jackson Lake which is 45 miles from the entrance to Yellowstone. Gros Ventre is on the "far" end of Grand Teton, much closer to Jackson but not that far from the Moose entrance so it's a good place to stay. Only reason I wasn't totally happy with it was the drive to the lake to fish as compared to Colter Bay. About 40 minutes from Gros Ventre to Jackson Lake from Gros Ventre as compared to less than five minutes to the ramp at Colter Bay. Also less fuel use as well. Liked Gros Ventre somewhat but since our main visit is for fishing Jackson Lake, we like Colter Bay much better.
As far as Yellowstone is concerned, it's not that far from West Yellowstone to get into the Park but for seeing the Park, you might be better off trying to camp inside if you can. Yellowstone is pretty big, about 140 or more miles of roads as well as all the hikes and features that you can't really drive to. Enjoy your trip and if you don't need FHU, Gros Ventre or Colter Bay campgrounds will work great for you. Grant village, a ways from the South entrance is a nice campground on the West Thumb of Yellowstone Lake which, in itself, is huge. It's over 20 highway miles from Grant Village to Bay Bridge and the Lake Hotel and Fishing Bridge campground.