I would only consider leaving the parks on a first visit, if you have more than one day planned in that park.
Some people underestimate how long it can take to get to AKL from AK. It's a big park than can take significant time just to get to the exit much less getting to AKL from there. DH & I once left the Lion King show with 1 hr. & 20 mins. to get to Jiko. By the time we walked to the bus, waited for it, then rode there, DH had to run ahead of me to make it to the restaurant in time to check in. (You can make it faster, but it's not like leaving Epcot or MK to go to a nearby resort.) There's no way I'd leave AK to eat at Sanaa, if I was planning to return to the park, especially since you'll only have one day there. IMO, none of Disney's restaurants are worth losing that much park time on a first visit. If I were you, I'd consider Tiffins or Yak & Yeti instead.
You've already chosen not to go to Disney Springs, but I think that was your only viable idea. Although Epcot is my favorite park, most people don't need a full 2 days there. If you still want to see DS, I'd consider going for dinner on the evening that Epcot has the earlier closing time.