Boston is easily accessible by plane, train, automobile or segway. The wedding venue is close to both Logan Airport and South Station. You don't need to rent a car unless you want to take on some adventures outside of the city. Subways are convenient and cabs aren't too expensive.
Sure it's winter, but that doesn't mean you have to stay inside all day. Just bundle up! Boston has loads of great history and culture to explore. Below is a short list of some sites/activities that we recommend checking out (brewery tour, anyone?).