Every summer I get overtrained in the legs due mostly to running and bicycling. Usually this starts to resolve itself around August, but I find it necessary to take an entire week off at some point, usually June or July. The problem is that getting in shape after your low 30s takes a certain amount of maintenance just to retain your base fitness. Making progress becomes more difficult than it was in your 20s.
Taking an extra day off means that your next workout is not likely to make forward progress. Instead, you will merely be preventing yourself from losing your gains. Speaking from experience, after age 34 to 35, gains tend not to be loyal.
If you take two extra days off, you will likely lose some small amount of fitness and need more than two workouts to get it back, in addition to normal recovery days.
If you take an entire week off, it will take more than a week to regain your fitness. I'm 46 and it seems to take me about 10 to 14 days to get back to where I was before I took time off. Since I took time off in the first place due to being overtrained, this assumes I can avoid injury or going into an overtrained state again.