Which hotel? Which bag check? Saturday is a MM/EMH at DL (which I assume you won't have?), so give yourself plenty of time (more than you think you'll need) just to be on the safe side. The lines to the gates have been backing up heavily on Saturday mornings.
We'll be about a mile away, so I think we'll just use uber since it's only a 5-6 min drive. We'd be coming in through the Harbor entrance. Was thinking about leaving the hotel at 7a. Would that be cutting it too close?