Wow! I hadn't seen anyone write about Harrison Pass until now, so I went looking. I see it is an alternate route -- you would continue down Bubbs Creek to Junction Meadow, then climb south to East Lake, continuing up toward Lk Reflection, then heading east and south up toward Harrison Pass.

Using a Cal Topo map and also Google Maps with satellite view, I can see a faint trace of an old trail in a very few places. But you would be mostly hiking cross-country between East Lake and Lake South America. I think trails to East Lake are ok, and I am sure from Lk S.A. the trail is good.

I am sure it can be done, but travel would be slow. I seriously doubt your group of 14 would agree to do that. Maybe several hardy members might like to go for it.