Even riding the ferry across the Hudson from NJ to NY is quite an experience in winter.
You've never been to NC, have you? They may have some breezes, like us, but they don't have to dodge iceburgs. Do you really think it will be easier to drive across a high level bridge in the wind and icy snow?
I beleive their underlying premise is that an airport exists on the island, which needs better access. IMHO, it would be better planning, AND EXPENSE, to look for a mainland site.