Well, today I rode Endurance 2.5 for 2 hours and 48 minutes. My plan was to dual record while riding Alp du Zwift.
Well, Zwift had an update which took over 30 minutes to install. So I had a nice long warm up in level mode while waiting.
But, in the end it loaded and I started it up. I rode the climb in 78:44. I used my easiest gear which was 39-25 (not ideal) on my KCore (which i am in the process of getting repaired/replaced because of some vibrations, etc). I’m not light. 182lbs / 82.5kg. My FTP is around 245-250.
So, I rode it at an average of 47rpms. Ouch 
!! I just kept repeating three things to myself “shut up legs!” and “you can do it,” and “just keep riding.” Eventually I made it! And I set loads of segment PR’s. But that’s likely because most of the time I dial recorded and didn’t use the gradients, so I never saved those workouts and this is the first time I rode it all the way from bottom to top while letting Zwift control it a 100% so I didn’t delete it after.
So, it looks like my legs aren’t in too bad of shape. New KCore should arrive in about 7-9 days. It’ll be touch and go to see if I need to push things back into December. I’m about 50/50, depending on which half of my brain I’m using at the time. 
I just have to do some days of multiple rides to see how they go.