I'm a bit confused by your post: you mention "riding to the trailhead," which implies you'll be riding on trails, but then "participating in group rides" which implies road.
So, am answering with use-specific recommendations:
if you're going to be riding trails, get a mountain bike. Designed for trails, more comfortable, and easier to handle on trails.
if your "off road" riding will be only the gravel road to start road rides, and you're really serious about group rides and RAGBRAI, get the Avail (note that there are other brands with good, inexpensive stuff - I like Fuji and Specialized for that range).
However, my real recommendation is to get the Escape. You stated that you didn't really like the position of your Schwinn, and the Escape gives you the option of staying up on a flat bar (comfortable, especially for a 55 yo restarting cycling), and it has a more relaxed geometry. And if you get serious enough to do RAGBRAI, you'll probably end up upgrading anyway.
Good luck!