This from @sbhigham is pretty accurate. Double the timeframes if your org has more than ~50 people in Digital/Tech. Double it again if you have over 250.
This is why I advise orgs to not forecast any more than 1 Quarter into the future. Beyond that, your confidence interval is probably somewhere between 0-25%.
I could write so much on this, but it’s all been said so many times. If you’re not interested in learning why and how to handle this uncertainty, you’re just not trying.