How long does it take tolerance to reset?

Over about . . . 7 years or so of drinking, with the last one being particularly heavy, I’ve developed a really insane, unhealthy tolerance. I’m talking . . . over a liter of vodka before I pass out and maybe not even then. No amount of beer even does anything more than slightly buzz me anymore. And never a hangover the next day.

So, if I want to go back to the good times when a way more reasonable amount could impact me, how long would I have to abstain from drinking for a reset?