I TOTALLY slacked off at the end of last year from May through December... did some riding but really off my normal amount. I decided to do that strava challenge (Rapha 500) which is 500 km in 8 days. I made it but my ass was hamburger. Ow. I ended up buying a new saddle but I think the real issue was lack of readiness. And I had a nice saddle and nice bibs too, the issue was purely me.
Between that and a good month of January I was probably back to where I was after that 5 week period. Close enough, at any rate.