I did an overnight itinerary a couple years ago on US (DCA-PHL-SJU) with a 10:00 pm departure out of DCA and a 7:45 am flight out of PHL. Agent at DCA gave me the choice of checking bag through or claiming it in PHL. We opted to check through.

But 23 hours in MIA....I'd definitely claim it. If you want to leave it checked (if that's even possible), I would leave -nothing- of value in the bag. And I mean nothing.