We have spent the last couple of winters afloat in ConwyMarina which is more sheltered than most and has some very reasonably priced tradesmen to hand if needed. There 's hard standing there too if you prefer. They keep dredging the marina so as long as they put you in a dredged berth you would be OK. Entry to the marina for you would be an hour either side of high tide. Passage to the isle of Man is about 50 miles.