Upvote:1
Many of the "old folks" tours also have middle aged adults participating. While they target the older working folks and retired crowd in their advertising because they have the time and money to travel, you often see adult children accompanying their parents or middle aged couples or singles.
There are no guarantees you will find a same aged person on your trip, but likely there will some nearer to your age.
Actually come fall you may even see grey hairs in the Contiki tours ;-)