@ SVCarolena, I wasn't aware that the Potomac froze over. I figured there would be some ice along the edges, and perhaps some chunks floating downstream which would present a hazard to a boat at anchor, but I guess I thought the Potomac had enough current and volume for it to freeze.
Then again...I suppose a long enough freeze and it certainly would/could freeze over. We are quite new to the area, and I feel like a sponge soaking up all the info everyone is providing!
@happypappy, can and does freeze in a tough winter like the last one, which is why the places I mentioned move liveaboards to slips in the winter.
@auspicious, sorry I don't have the bandwidth to search for a reference for the two-week limit and don't remember where I read/heard it, will look when I'm back to the land of unlimited internet in a couple of weeks if no one else comes to the rescue before then.