If you want to ride in a group, listen to 10Wheels, especially regarding mileage. In addition to that, consider adding rollers to your indoor training tools. Back when we were young and fast, my wife could barely hold 20 mph on her own but would ride for hours with a group of us who cruised at 28 mph because she could sit extremely tight to the wheel in front of her. She could do that because we all rode rollers as a regular training method. No squirrels were allowed to ride with us.
You'll still be on your own on the inclines, but at least you won't get dropped on the flats.