How many days do you realistically plan to ride there and back? There's a huge difference between riding 18 miles a day and 30 or 40. Add in the cold factor, too, pulling dogs in a trailer, and riding with people who aren't as fit as you. I second the idea of hotels and maybe your mom and DH sharing sag duties. Maybe I lack the sense of adventure you have, but I know I would want to train a lot more for this type of trip. There's nothing worse than feeling miserable on a multi day trip.