We had the opposite experience than many. Stayed at Cherry Hill on Independence weekend one year, the 4th was a Saturday. The crowds and traffic were very manageable in my opinion. As a matter of fact we expected it to be swamped, and was actually quite a pleasant trip. Obviously I'm not talking Memorial day as the OP. We speculated that because the 4th was on a Saturday that a lot of the people that actually work and stay in the city went away for the long weekend. Anyway, I would give it a shot, had a blast when we were there.