I have my own rules about winter backpacking. I would not even consider going out without committment to stick together. It has nothing to do with age - if I asked someone 20 years my senior to go with me, I would do whatever necessary to allow them to keep up; if I were to ask someone 20 years my junior, I would expect them to slow down and go my pace. We would have a meeting spot at the parking lot and stay put until everyonen showed up. I do not think you are too old- I think you went with the wrong people.