I would think long and hard about an extremely small, light weight 4x5 camera.
In fact I have and the answer to me was the, "Excursor I" camera manufactured by Argentum in Hungary.
This camera is extremely light according to the manufacturer, the weight is 0.8kg. Allowing for a lens and two film holders and a small light meter, about 2.5kg.
Now even allowing for some fudging, this is pretty much lighter than any current camera for this format.
There are drawbacks in that you cannot change the orientation from landscape to portrait, if it is a landscape version. Or the other way around if you have a portrait version.
An 8x10 camera in this model range is quoted at 990. The 8x10 camera weighs 2.1kg.
If I wish to do 8x10 contact printing in the future, then this camera will come into contention because of it's extreme light weight, compactness and ability to obviously be carried in a backpack with relative ease.
Even if you start carrying something like this through Brindabella or the Snowy Mountains, you should be able to still walk and talk at the end of a day
Mick.