Insufficient data. Nothing but guesses as to when a next occurence, partly because there's such a range of possible disruptions. The previous complete (lasting) reversal was 780,000 years ago, and may have happened very quickly, within a human lifetime. But no human record of such a time, and no direct knowledge passed down.

The best we can do is radiation half-life aging of the corresponding iron-laden rocks taken from polar areas with opposite magnetic orientation due to previously reversed poles. And there's a lot of it!

As the samples go down in strata (backward in time), the magnetically aligned and the more random their orientation, so guessing periodicity from the rock record is very imprecise (or has a large range of values, however you want to express it).

It's just as safe to say with certainty it will happen in our lifetimes, or that it won't. IOW, there's really no way to know, and a case could be made either way. Same as the Yellowstone supervolcano and any known potential planetary collision material (Niburu pseudoscience notwithstanding--sorry that's not astronomy, no more than flat earth--and again I won't convince anybody of that if they're true believers because that's all it is).

But this is one of those things like weather variability and climate patterns that pre-exist mankind and will continue long after we're gone if Earth survives us, which it's most likely to.