We had no problem using Uber and Lyft between the hotel (the aforementioned Hampton Inn) and the ballpark. Never waited more than about 5 minutes for pickup and the fares were pretty low. You could probably stay closer to City Walk and still uber/lyft back and forth with no problems[...]
What about regular taxis? (Uber/Lyft aren't options for me since I am not owned by a smartphone.)
Not looking promising - would love to check out Nats spring training (having caught many such matches on the radio it sounds like a great way to ease into the season) but Europe is oh-so-much cheaper, safer and more accessible.