You can check in first thing in the morning of your check in date. I dont believe you can check in before then. Official check in time is 3pm on the date your reservation is for, but you can check in earlier on that same day, get your park passes etc and enjoy the amenities of the resort or head right to the parks. Your room may or may not be ready if you check in early though so be prepared for that. If you are staying offsite that shouldnt be too bad. I usually carry a gym bag with me with a change of clothes (shorts usually) a travel size tube of sunblock and my pack I use when I run in the parks and I am ready to go!!! Have you thought of adding a night onto your current stay to minimize your having to get to the offiste hotel, unpack, repack the next morning etc? Have a great trip! Belle