For my part, I never really got away from things and have had quite a slide anyway. The closest I've come to letting it go, mileage-wise, was dropping to 80-90mpw from the 100-140 I usually did. At first, I went a little faster on the lowered volume. But then I started slowing and nothing reversed it, including stretches of time when I went back to the 100-140s.
As time went on, I think I exacerbated the process by racing less frequently, partly because races had changed from being venues where I saw myself improve to venues where I saw myself decline, which is generally less fun.
Now, I don't know how bad things would be if I'd just stopped running for 10 years or so. I might be more morivated to race now had I done that simply because I'd have come back with no expectations.
I also wonder what would happen if I went back to the 100-140 stuff for two or three years rather than for six months, which is about the longest I've sustained really big volumes in the last 25 years.
On the other hand, I get hammered at races frequently by people who do about half of what I currently do. So I also wonder if I'd be better off running even less than I do now.
I'm not sure what the point to all this is other than to suggest that there are no automatic answers.