That's not a high mileage for an 80 series, really.
We used a LC in Tanzania which had 530,000 km on it: the speedometer was not working and we asked how long ago it had failed - the answer was "No idea, it wasn't working when we got it 6 years ago".
We met a traveller in Argentina whose LC had over a million km on it.
However.... expect to have to fix stuff, and be prepared for failures. Our 80 series, in two years of ownership with 325,000 km on it at the end of this period, had the following failures, despite rigorous maintenance:
- miscellaneous electrical problems during a week's travel, finally resolved by a great specialist in Victoria Falls, however during the week we were stuck several times and needed "first aid" fixes.
- A/C fan motor wore out - replaced after a couple of months wait for a new one from Dubai - we spent the time travelling with no A/C, which was OK but not as comfortable as preferred in Southern Africa.
- Radiator exploded - we found the only replacement available (new or used) in the country and replaced it - rented a Ranger for a week while this was being done.
- Front differential failed - fixed in Kampala, which took a week, during which we rented another 80 series. The failure was in Murchison Falls and to get to Kampala we disconnected the front prop shaft and the hubs, which meant that the hub seals were not fully protected (despite temporary covers). As a precaution we replaced the seals, but.... the new seals which we could find were not OEM and one seized after only about 500 km, shearing the hub. So we needed a new hub and this time found OEM seals and replaced both.
My point here is not that you should not make the trip, we were happy with our vehicle and had great travels in it, however you should expect to have to fix things, which may mean a long wait, and you should always have a Plan B (and a Plan C).