I have the place for you debster. We went to stay at this hotel just before ds was born. Been back there a couple of times since... Really can't fault it.
It's called The George Hotel in Yarmouth (IOW). It's next to the ferry terminal - you get the ferry across from Lymington, and then it's a small drive around the mini one way system in Yarmouth.
Fab bedrooms, fab service... attentive but not too daunting, IYSWIM, views across the Solent. Food so good you really won't want to go anywhere else. Got a posh restaurant and a brasserie.
Only thing is... no pool.... BUT you do have your own private beach!!
No real idea of cost, but every time we've been, its been on a "Deal" basis. Give them a ring, and see what they have to offer. Never seen any small children there, so expect reasonable peace and quiet. (Dunno about you, but when I leave ds at home, last thing I need is to put up with someone elses!)
Have fun. Can I come too??