I was only able to confirm two parks in the northeastern USA that a) have northeast-facing shorelines, and b) are publicly accessible before Sunrise: Assateague USA National Seashore Park (Berlin, Maryland) and Presque Isle Pennsylvania State Park (Erie, Pennsylvania). It will be raining everywhere in Maryland, but currently forecasting as mostly clear to partly cloudy in Erie.
Presque Isle will also have both a greater eclipse magnitude and eclipse duration than Assateague, so overall is a better choice than Assateague (other than a slightly lower maximum Solar altitude angle), even if it wasn't raining in Assateague. I spoke directly with the park rangers, and confirmed that the park will be open at 5 AM for the Solar eclipse, and there are no permits needed for setting up telescopes or tripods. There is no entrance fee to enter the park, and the restrooms are open and available at 5 AM. There are also no pandemic travel restrictions for entering the Commonwealth of Pennsylvania, though of course you should be fully vaccinated for COVID-19 before traveling.
There are still a number of hotel rooms available in Erie as low as $59. Going to try to get there today so I can maximize my sleep tonight. I will be bringing at least 8 pairs of eclipse glasses, 1 Solar binocular, and 2 Solar telescopes. Remember not to look at the Sun without eclipse glasses, even at Sunrise!
Here is a photograph of Presque Isle facing southwest (northeast is in the direction of the camera). Note the northeast-facing shoreline and low land of the isle (though technically it is a peninsula). The park rangers recommended either Beach 9 or Beach 10 for the best northeast-facing view. The park opens at 5 AM so that gives 47 minutes to scout a location and set up equipment. And no worries about saltwater seaspray on a freshwater lake. Swimming is also permitted on the beach.
Presque Isle - mostly clear to partly cloudy
* eclipse altitude 7.7 degrees
* eclipse duration 52 minutes (5:47 to 6:35)
* eclipse magnitude 77%
Assateague - raining!
* eclipse altitude 7.9 degrees
* eclipse duration 49 minutes (5:38 to 6:27)
* eclipse magnitude 61%
Edited by Nicole Sharp, 09 June 2021 - 11:00 AM.