I love Portland ME - it isn't a huge city, but maybe you would like some of the towns in that area. There are alot of pretty seaside towns where you do not have to drive a long distance to go to a grocery store. I'd say almost any of them near the Portland area. And it wouldn't be as snowy as say being inland more or towards the mountains.
And yes the ocean water is cold - you can maybe swim in it in August. Although kids will swim in the ocean pretty much June - August. They don't seem to mind the cold water as much. The summers are beautiful - the winters very cold!
The one negative is many of these seaside homes will have lots of tourists in the summer.