The 2010 roster had a lot of players that continued to contribute for many seasons after that horrible season, some that were on the 2015 Superbowl roster. Some notable names:
As far as a hypothetical 2020 collapse, other than Christian McCaffrey, I really don't think there are many players that will be contributing to a future playoff run. Half the roster are free agents this offseason. The team is going to look so much different next season it's pretty fair to predict that Ron Rivera would lead the team straight into the abyss the way things are trending.