Not to hijack, but I'd like to assess my fitness too:

I usually do one ride every day, so about 9 rides each week. Ride length is usually 1-500 miles.
I average about 27 mph, solo, give or take depending on traffic.
I'm just wondering if I'm fit enough to be able to hang with the recumbent group.

Ahhhh yes. The main reason I try to ride in large groups. Safety in numbers.
These old people are blind and deaf. I had an old guy cut me off and I screamed at the top of my lungs and he never looked at me. All while I was doing 1-500 miles at 27mph average, daily.