Like most shore towns, Ocean City is tight for a 45' to park and navigate. Hopefully you have a place to park your rig on the mainland.
GSP is fine but you should get an EXPass to save time/aggravation at the tolls. You will have to get use to getting the motorhome through a toll booth. Use the booth on the rightmost side for some additional width.
I usually go GSP to NY Thruway and hop on 90/Mass TP right before Albany then to 91. CT traffic can be just as bad an NYC traffic. As stated above, stay off the GW Bridge - if you do end up on it, you MUST take the upper level.
Tom and Katharine
'07 Winnebago Tour 40TD, 400hp Cummins
'17 Winnebago View 24V, '02 R-Vision B+
RVing for 20 years & 200,000+ miles