We have friends who have for years belonged to a similar group that offers free lodging to member families who are traveling. We've met some of their guests and they've been delightful. They'll just get a phone call saying "such and such a family will be traveling through your area on such and such a date and need x-number of beds or sleeping surfaces. Can you accommodate them?" They usually end up putting all the kids (from both families) on the floor and couches. It's generally only for one or two nights and they aren't expected to provide all the meals, but breakfast is always nice.