AA's policy is 4 hours at DEN, FLL, LAS, MCO, SLC, and SEA only (domestic). But, you won't be able to check your bags for the next AM as you plan. Depending on the departure location, the easiest may be to have the bell desk at an airport hotel store the bags for you and pick them up the next AM. It will take a very decent tip, but it's easier than lugging.