Four Seasons won't always allow us to bring our two dogs unless we book two rooms. Our dogs are ~40 lb. and ~65 lb. Some hotels have a "combined weight" allowance (i.e. 75 lb. total). One hotel that I looked into has an 8 lb. limit, so you could really only bring a hamster there! Both of our dogs were rescued as pups, so we had no idea how big they would be.

St. Regis Bal Harbour, for example, only allows dogs under 25 lbs. It's so difficult to find a luxury hotel that allows two dogs with one being >50lb.