I love canoes, and although I'm the least snobby person in the world, this is something I feel quite strongly about. So here's my take on them.
Even counting the added convenience, inflatables are just not worth it. I know of quite a few narrowboats that contain deflated canoes of varying levels of mouldiness that were bought on a whim, then put away because they just aren't that nice to use. A skeg might help a bit, but it will still end up all over the place when it's windy. And you'll end up getting wet if you're sat there for more than ten minutes, which is OK in a lake but never nice in a dirty canal.
I'd buy an open canoe now when they're a bit cheaper, and sell the inflatable when the weather's nicer. It's better value in the long run, as you'll use it that much more, and if it doesn't work out you'll get your money back!