Well Alex, Is it tippy? Yep! Is it manageable? I'd think so if your willing to (once it warms up) play about in it and find where that point of "whoops! that was too far!" is. Seriously, for me at least, playing in the canoe in shallow water has always been informative if a little damp. And a great confidence builder. Of course always wear your PFD.
Now, looking at the pictures of it: looks to have no carrying thwart, not good at all. One seat, can you kneel comfortably against it? I can't imagine paddling that in any other position other than kneeling.
You talk about overnight trips, don't know where you are but surely you have some camping gear along? Is there room enough for you and your gear?
Here's a generality and certainly open for argument but: most of us start out with a 15-16 foot canoe. A craft about that size seems to work for all kinds of folks, in all kind of situations. Before I'd go bigger or smaller I'd want to have bunches of experience and a darn good reason to make the change.
Say...you started that thread about axes and we've had buckets of fun with it, Thanks!
Best Wishes, Rob