We're planning on having my rehearsal dinner at my parents' camp on Lake Superior. I don't want to invite too many people because FIs parents have offered to cook everything. We have a lot of friends/family coming into town just for the wedding and I want to give them something to do. Would it be ok if we invited them out after the dinner to have a drink with us and sauna? They're all invited to the wedding and I don't think they're expecting to be invited to the rehearsal dinner...