No bike is 100% reliable.
When the bike brakes down it will be a long way from someone who might know about that particular model.
The things you can do;
Fix it yourself
Try to get someone there to fix it
Have it transported to someone who might be able to fix it
Isolate the smallest bit causing the problem and take that and yourself off somewhere to get a replacement
Depending on where you stop, the local conditions and yourself this may be a very good part of the trip- you get to meet the locals rather than just ride past.
You will need to learn how to fix the bike ... at least that is the best method ... otherwise you are in the hands of a 'local expert' who may damage the bike further.
MESSAGE .. learn the basics of your bike before you leave.
Get a knowledgeable contact who is willing to help by phone/email.
Get a supplier who knows how and has done shipping to the places you are going.
Even if you are fortunate enough to have a local expert, your knowledge at least lets you understand what is going on.
What most people who talk about 'off road' mean is 'off a sealed road'.
Riding a bike off a sealed road with luggage is enough work without making a new road too.
Not to say there are not enjoyable bits about the nonsealed roads, getting to places others don't (less people, more room), seeing some magnificent bits of the earth.
Do try and keep the weight down. A lighter bike with less luggage weight does make riding on sand/gravel/dirt/mud easier. Think about what speed you want to cruise at and select a size of bike that will do that speed rather than selecting one that meets some image thing. You'll be happier on the remoter bits of the trip. Good luck.