I have been given upgrades with remarks like "Good thing you got here early, this is the only upgrade we will be able to give today". Generally, it depends on when the upgradable room is cleaned. If I can arrive early stop at the desk and ask to check in and get an upgrade. If none is available ask if they might save me one and I'd come back later. This often works. Make sure and ask when that person is off duty for the day. They are much more likely to help you if they know that they will see you again. When I return, if they say, "no more upgrades”, I politely ask for a manager and say that I have been waiting all day for an upgrade and now there is none. I have been upgraded to some nice suites under this scene. I only do this with multi-stay days.