Just a little food for thought. We went one labor day weekend, ran into a number of parties, that were not summiting. We gave it a try, and did not make it either. Most of the glaciers were hard ice,open crevasses, and the main shrund was not passable. Bonney pass without snow on it is miserable. Im not sure how the snow is this year? Maybe as the time gets closer, you can find some condition reports of the glaciers. Did it this way again in early July, and it was a cruiser!
TOURIST CREEKST(not Wells Creek) might be an option for you. This is one of the shortest ways to climb Gannett, it hits gannett from the west, which is different from all other approaches. There is only a short section on Minor glacier,and The rest is fourth class, on good rock
There is a total of eighteen miles one way, 12 miles is flat hiking through Green River lakes, some truly awesome country! The next 2000 vertical feet is tuff. There is a faint trail through the trees that gets you up to a lake.(a good place to camp, but a very long summit day) From there a good detailed topo, can get you to minor glacier, and up to the top.
Love that place wish I was going! Good luck.