With the amount of riding you do, you should do fine. That is about the mileage my wife and I use to train for our longer tours only without the centuries.

A few years ago my wife averaged a little over 50 miles a day for 74 consecutive days on a fully loaded touring bike; so no, that is not too much riding for someone in reasonably good shape. However, she was a comparative youngster, just in her early 50's