I like to stay to the wide parts of the Potomac and usually head towards the Bay. There are so many nice places to cruise in that area and, where I am at, the slip fees are really reasonable. I can make Smith Creek, St. Marys, Kinsale, The Coan River, Bretton Bay, Leonardtown, Canoe Neck Creek, Cobb Island, and a few other places in a reasonable day's sail.
You are right about the winds up river. East of the Rt. 301 Bridge the river is much wider and a little deeper. The winds still love to go North West or South East (usually when you want to head in the direction it will blow from that direction). Occasionally we will get a South West wind and that is LOVELY sailing!