So, I'm planning an expedition to Oymyakon Yakutia (Sakha Republic Siberia Russia) and finally on to the Kamchatka Peninsula to the city of Petropavlovsk-Kamchatsky. The trips entire route from the Czech Republic to Kamchatsky is about 10,000 miles maybe 11,000miles. It isn't clear exactly how far Oymyakon to Petropavlovsk-Kamchatsky because well no roads exist between the location. My preferred vehicle is a 406 series Unimog. I plan fitting it with 200-225 gallons worth of diesel fuel in the bed. That should give me a range of about 2000 miles on roads. I'm not sure what terrain is like completely between Magadan Russia the last place in Siberia where roads connects and Petropavlosk-Kamchatsky is like. I'm hoping to average about 5 miles per gallon for fuel consumption. However, I also plan on carrying another 200-300 gallons of fuel in a small off-road trailer behind the truck. In addition to this fuel supply I also plan on carrying 50 gallons of fuel in Jerry cans as extreme emergency fuel. The total range I'm looking is about 3000 miles with the truck and trailer combination.

This will be my first expedition in a Unimog 900. I have limited experience with the U900 mog. However, I like the capabilities of the truck. I'm planing on purchasing a U900 series with 110hp Engine and 20speed gearbox. What sort of upgrades would you suggest that I put on the truck make it capable of driving in Siberia in -40 to -70C temperatures. Also any other equipment you can suggest I would greatly appreciate as well.

Thanks