In reply to Iain Thow:
That should be fine for snow - by late august the mozzies are usually gone. My main trip was in early June to cater to my pathological dislike of mozzies - definitely a mistake!
Also went in winter and failed to allow for acclimatization - another huge mistake! The latter trip also taught me that serious winter camping (i.e hauling a sled) is a bit of an acquired taste.
It's just a magical place, though.
Titcomb basin doesn't have any high-ish passes to cross for access (so easy even if there's still a bit of snow), but it does have a flattish walk in so great breeding ground for flying things. The Wyoming mozzies are slow and dumb but do have remarkable penetrating power, so it might be a good idea to grab some hats with a mesh screen "just in case" while in Pinedale.
The other issue is wildlife - note the bear hangs in the trip report (which really captures the feel of the place - a mixture of intimate and grand at the same time)