It's very difficult to say exactly how far you could go. I'd only expect it
to get you about half way back to the Jiffy-Lube that left the drain plug
out.

General rule of thumb for chain driven transfer cases is that if they
have been driven at all (any distance) without oil, they should be
rebuilt/replaced.

Since it would be impossible (as I see it) to not drive without oil,
I'd say your best bet is to assume it is terminally damaged, and start
considering a rebuild, before it fails completely.

Note: most chain driven transfer cases, when the chain breaks or
stretches enough to jump teeth, self destruct completely as there is
insufficient clearance between the chain, gears, sprokets and the
case.

No your question is not weird! <g> I've seen transfer cases drain
themselves from time to time... One case (used in Hummer H1s) is well
known for loosing a small rubber plug (which is well above the oil
level!) and then draining themselves. The owner, unless they park in a
garage where they see the oil dripping, never know until it breaks.

Don't think anyone can state an exact so many miles.  Years ago I had a
manual transmission rebuilt at a shop.  They forgot to fill it with oil
when done.  Drove about 80 miles on the highway when all of a sudden the
rear wheels locked solid.  Got it home and opened it up and the gears
had literally melted together.

I'd say fill it up and see how it goes.  Odds are if it were driven more
than a very short distance it will need rebuilding.

I was once driving a Chevy S10 Blazer some years ago at highways speeds. It
had Castrol in it.
All of a sudden I lost power and could go no faster than 55. No warning
lights or nothing indicating a problem.

I got home to check out everything on the vehicle. Turned out all the oil
had drained out somehow, and there was none in the drain pan.

While the engine still ran..it needed to be replaced.