How fast can you run down Main Street?
I think you can do it, but you might be a little late. That said, you should have a 15 minute grace period. I'd still keep looking for a 4:15.
You will want to be at the front of the line for early party entry so you don't get delayed behind a crowd all entering at 4. We did this once with a 4:10 ADR at CRT. They ended up letting people in around 3:50 so we had no problem at all. But you never know how it will go on your day.