Howdy

Are you running a spreadsheet to record your costs? I am somewhat obsessive compulsive with spreadsheets but they can really identify where efficiencies can be found to lengthen the trip.

Are you 100% committed to taking your own bike, or flexible?

The reason I mention this is prior to covid I began planning our trip OS with a vehicle and the costs were much more than I thought they would be, once everything was recorded. I then did the same without taking a vehicle and the savings were stunning.

This was for a 4wd and a family of four and I expected the transport savings were going to be much better taking the vehicle, but surprisingly those savings were not there, even using public transport for many areas. (you would think 4 in a car would be cheaper than public transport but over the whole trip, not so).
The savings available on Skyscanner website were pretty stunning.

Based on your costs, 16% is just transporting the bike.

Broken down your trip seems to be;

Outer Eurasia
Asia
South East Asia
South America
North America

The outer Eurasia could be done as a loop on your bike. Arrive back home, rest up for a week, and head off with your soft motorcycle luggage to wherever the cheapest flight gets you. Buy a bike that suits the country you are in and use it to do a big loop of wherever you can go with it, arrive back and sell it.

Rinse and repeat.

Just a thought.

And it saves you gifting your bike to that nice border guard in Bolivia when Covid 2.0 strikes;

"Lo enviare, confía en mi"