Great plan! It's closer to a 20-min uber ride, but should still work.
LIS is not YOW in that it's busier, but if you get back to the airport at T-70 you shouldn't have any problems.
I imagine you'll have about 4-4.5 hrs to walk around. Be aware though, if this is on a weekday, the ride back to the airport may take a bit longer (though still not more than 30 mins), as rush hour starts around 5:30PM.