I hear you!
I lose so much sleep about snow cancelling flights!
We have often done the trip during March break. As far as snow our thinking has always been that if we make it to Boston, there will be much more choice of other flights if ours is cancelled! A smaller airport doesn't have alternatives, which is why we've never done Allegiant from Bangor during the Winter.
In theory it doesn't matter too much if you miss a day or so of your vacation but if a cruise is involved you have to get there!
This March i'd even planned out how to drive from Boston all the way, incase bad weather cancelled flights! There was no way I was going to miss the boat!
Although we're at the smaller manchester airport next March I know we're close to Boston or NY if we really need to make other plans!
And we always get insurance!