Little morsel...Revit won't let you enter a value greater than 3000 ft (or 914400mm) when moving or copying an object for example.
Revit won't object if you pick two points that happen to be further than this though. Hopefully you won't really need to move something down the street this far but if you do, you'll be ready.
Why do I know this? I encountered a file that had civil data positioned 2.6 million feet from the original drawing area of the Revit project file. So moving this in increments of 3000 feet was going to take quite awhile, 867 times give or take a repeating decimal. So I thought, hmmm...what if I just pick two points? Happily Revit just moved the stuff over 500 miles for me in one go! Hooray!