If you misconnect, you'll get put on the next available flight. As soon as you know this is going to happen (i.e., before you leave BOS while you are sitting at the airport) call and get rebooked.
If you're concerned with the cost of a hotel room, you can buy cheap travel insurance that will typically pay you $100-$500 towards the cost of necessary expenses for the delay.
Look at what options you have for later flights and check seating availability. If you are trying to get to you destination by a certain time and things don't look favorable, you may want to pay for the changes and fly out the day before from BOS.
There is not much you can do right now as no airline that I know of will be rebooking anyone [for free] on their hunch of a misconnect.