It's not the "Snowmageddon" of two years ago--in fact, we barely recognize what snow is anymore around here, and I haven't even seen any TV-weather-forecast-induced supermarket panic buying sprees yet this winter--but transit remains an excellent option for two reasons this (and every) year for the Max's Belgian Fest, now in its eighth year.
New this time around is the FREE (for riders) Charm City Circulator Green Route, directly connecting the Baltimore Metro's Shot Tower stop with Fells Point. Study the route map.
MTA Maryland's web site. Bus Routes 11 and 10 are the closest to Max's, with 21 and 13 being of some use. Other routes are on this map. A day pass at $3.50 is just a little more than two trips on the bus or subway, and makes handy insurance if you need to be flexible in your times. Be aware that if you stay until last call, your options are severely reduced. Metro stops running at midnight, for all practical purposes, and "night owl" bus service is few and far between.