Who knows! It’s Montana. Would plan for 70s with chilly evenings and nights. It could also snow though ;). Be prepared.
Ultimately this just means dress formal. We wouldn’t hate a little western flare though!
Tough question. The northwest entrance is about 30 minutes from the venue but Yellowstone is quite large. The south entrance is about 4 hours but a lovely drive through the park.
Livingston is the closest town with most major needs and is about 25 mins from Emigrant. Bozeman would be the next closest more of a city with just about everything you could need and is about 45 mins from Emigrant.
If you’re planning on hiking or anything off the beaten path, I would recommend having bear spray in this area. Especially near or in Yellowstone. Let me know ahead of time and we can provide you with some hiking ideas as well as bear spray.