Hello Haris,
If you have an AWD/turbo version this car is much capable of being head to head in comparison to a 1300-1500 cc Vitz. I have personally done some 0-60 mph runs and was surprised to see Mitsubishi i Mivec lead with the initial acceleration.
A turbo charged engine offers higher acceleration and torque from a low displacement engine. Having said that I would advise you to keep an extra fuel-CAN, as it would be much higher on consumption. Reason being as compared to the conventional free intake, a turbo/forced intake takes in a lot more air along with the fuel to get that torque range for climbing up the hills.
Considering the descent clearance on this car it wouldn't have any trouble riding up with four passengers, However please be advised to take caution and pace the climb so as to not over stress the suspension. Mitsubishi i, offers an effortless drive and you wouldn't want to push that Electric Power Steering and active suspension too hard.
Good luck, and have a good trip !
It would be best to spread the word around. Feel free to share your trip photos and travel experiences
Cheers,
Abdul Wahab