Ceremony? Think: I want to look good for this party but I also want to be comfortable. Flat shoes or chunky heels encouraged for walking in the grass. Business casual. The wedding party will be in full formal wear for the ceremony and may dress down for the reception. Before and After? You're visiting a remote lodge in the mountains, think cozy sweaters, walking shoes or hiking boots for exploring the lake, and drinks by a fireplace.
Not if you aren't comfortable doing so. There are other lodging options on the travel page