We use our 19' two different ways: we take day trips on local rivers (Miss. and Illinois) and we have the boat at our lake cabin in Ontario, where we mostly take folks tubing/skiiing.
Our day trips on the river often involve beaching, cooking out, and tubing/skiing trips. It is easy to underestimate the amount of stuff you will likely bring with you when beaching for the day: cooler(s), maybe a grill, towels, chairs (maybe), skis or a tube, tow ropes, etc. That stuff, along with the full human and canine crew you describe, will feel REALLY tight in a 19' boat for an hour or two. You will be able to do, and once you beach and unload, that size boat would be great from hauling people around or making short excursions. But when you have all your gear and crew aboard, there won't be much room to move.
My friends with 'toon generally don't love them for their ability to pull skiers or tubers, especially after experiencing that on a runabout. They are ideal, though, for hauling lots of folks and offering a big comfortable platform for hanging out.