Go to Universal, stay in a resort that gets free express pass (because it's gonna be super crowded there too if Disney is sold out), enjoy the Universal parks, and go to Typhoon Lagoon one day to get a taste of Disney.
If you have time, you can also do a resort tour-- the monorail loop is nice. Park for free at Disney Springs, take the boat to either Port Orleans or Old Key West, maybe explore that resort and then take the bus to MK. Walk to Contemporary, explore the resort, visit the gift shops, go down to the docks, then take the monorail to the Poly and visit those shops, walk around, and get a Dole Whip. Walk along the water to GF, visit shops, sit down in the lobby and enjoy the ambience.Then walk to MK (or take the monorail) and get the bus back to Disney Springs. Have some lunch/dinner somewhere along the way. Not as great as a day in the parks but still a nice time!