Just wondering if you would consider an e-bike. You can make your rides as hard or as easy as you want by adjusting the level of pedal assist. I use it because I'm not as fit as I should be on certain rides (also my main commuter.) Their are a few hills that I can avoid the "walk of shame" by using pedal assist. I don't have the throttle hooked up on my e-bike, but that's also an option when you just feel like you shouldn't push hard (it does drain the battery much more quickly.) E-bikes can keep people cycling for long after many feel like they should have stopped.