I figured if Six Flags was in range, then going into the city wasn't that much further. Depends on the time of the day and where they're coming from.

Spy Museum in DC? It's pretty interactive and fun.

They're offering it tonight starting at 4 pm if you're still interested. Be sure to order early. They run out sometimes.

Close to Brooklyn, it's south of cherry Hill right near the Baltimore Highlands light rail stop.

Southwest area dog park in south Baltimore is usually pretty empty and has two fenced areas so you can just tell anyone that comes up that your dog needs space. Also overlook dog park in linthicum heights is better attended but has three separate fenced areas so you should be able to get some space there. Also if you don't mind paying for it, sniffspot lets you rent people's yards to play in.

Willy's Kitchen in Glen Burnie does Sour Beef once a week or so. Check their Facebook page for when they offer it.

Heavy seas brewery in Halethorpe does this regularly. Looking at their calendar, looks like they have an event scheduled for Feb 19.

A local self storage facility could be an option, some offer vehicle storage.

There's also a long term vehicle storage facility near BWI airport. Bwiboatrvstorage.com but probably more pricey (and presumably safer) than an self storage facility.