We originally owned at Grand Lodge on Peak 7 and now own at Grand Colorado on Peak 8. Both allow dogs for owners only, or owners exchanging back into to their resort. As mentioned not all units are pet friendly, so you need t9 request a pet friendly unit when you make your reservation. So far we’ve never had an issue getting a per friendly unit.
Pets are not allowed everywhere in the resort, notably, not in the elevators. You have to take the stairs.