I do not!
I had a very large buffer when I came off of hiatus, and I ended up using up the whole thing. Admittedly it's nice to not be working on The Comic That Needs To Go Up Tonight... but I don't really like being months and months ahead. It makes me feel so detached! I think my ideal would be, like, 2-4 weeks ahead at most.
Before the hiatus, I started the comic with a five page buffer, but once that was used up, I didn't worry about rebuilding it, so for most of its 3 year run so far it hasn't had a buffer. It does mean I occasionally have to skip a week, which I try to avoid doing too often, but buffers sort of inevitably disappear with me, so taking time off just to rebuild them feels a bit futile. I'd like to get a nice pace of being a page or two ahead, though.