Gila Wilderness in Late May

You’ll probably be okay with that gear in May.

I did a 100 mile loop there that explored areas from almost 11k’ down to near 5k’. Combined with the cold air drainage of the West and Middle Fork canyons I saw 20-30°F difference for the lows between camps.

You should be fine as long as you do not camp in the canyons, where it can be a lot colder.   I have gotten 6 inches of snow in late May on one trip to the Gila, and I have been too hot and slept on top of my quilt on another trip.   You can also wait to make the decision until you are within a week of your departure trip.

I just tested my 50 degree quilt with my light synthetic pants and down jacket at a cool and very humid 33 degrees and slept through the night so I think it should be fine on the Gila trip assuming I don’t experience the very left tail of the average temp range during my trip.