October wedding start time

5pm is way too late! I was a BM in my FBIL and FSIL's wedding in October, and their ceremony was at 5pm. They were late to start to begin with, and it didn't get going until like 5:10/5:15ish. After the ceremony, which took about 20 minutes, the photographer was rushing to take photos because they were losing light. Long story short, the pictures did not come out very good, and they were barely able to take any photos with the bridal party. We got like maybe 4, but not much variety at all. Bride and groom were pretty unhappy, but then again, they should've factored in sunset before setting the time. Their fault. You're doing the right thing by asking and thinking twice about it.
My suggestion is to start at 4:30 at the latest! Don't worry about the hotel check in. That's the least of your worries. Usually hotels will let you check in a little early if the room is available.
My wedding in June will be starting at 4pm. The earlier the better for me so I have more time to dance and enjoy the party since our venue only goes until 10pm

We are planning on a 5:30 start time but we are taking all photos before the ceremony, so I think it'll be pretty if the sun is setting towards the end of our ceremony. Our cocktail hour is outside but there are heaters and strung lights in that area, and then we'll move inside for dinner/reception. If we need to, we can change the ceremony to 5:00 so I plan on confirming with the photographer before we order invitations.