I've done dry January several times, and have never felt any beneficial effects as regards sleep, or indeed weight which is odd. I've given it up as a bad idea.
I tend not to drink Mon - Thurs but I'm not fanatic about it, if I get invited to a birthday do or something on those days I'll happily drink. But I do try to get at least 3 drink free days a week, preferably in a row so sometimes skip my Friday night drink if I've drank in the week.
Holidays don't count and I drink whenever I like.