I've had this happen to me...both when I check in way before normal check in time and after. Depending on the level of the property, I am usually offered a better room permanently, or if my original room is a nice upgrade to begin with, the front desk usually offers me an interim room to stay in while my upgraded room is prepared.

I usually don't have to ask, but I am a Diamond and this has only really occured at higher end Hiltons (e.g. Hilton Sandestin Resort in FL).

I've checked in early at Homewood Suites before, but usually I just wait around or run errands as in the OPs case and come back when the room is ready.

IMHO, unless you asked for some type of immediate solution (like another room) I wouldn't expect any type of renumeration.