As one of the members of the final drive failure club,
I can tell you that there are no guarantees and no warning signs (in most cases).
The final drive bearing on my 2002 failed at 14K and 40 miles into a three week trip,
it was a "bummer" for sure.
There are LT's out there with a hundred K without bearing failure,
I think we established that the failure rate is approximately 3% of all LT's.
So which group are you going to be in? the 97% or .........
If worrying about it is going to affect your riding pleasure,
then go ahead and change it out.
Personally I think there are many other mishaps that are far more likely to occur,
like for instance a flat tire, so are you going to carry a spare?
Of course not, and if it should happen a cell phone and a credit card will get you out of that predicament.
Now if any of Y'all want a spare final drive, I've got one for sale,
if you break down on the road I could "overnight" it to you,
if you break down within a days ride of me, I'll bring it to you.
maybe this will help you sleep better tonight