The Ideal Camera for Trekking - a wishlist

Background

I recently did a high altitude trek in Sikkim.  I had a full-frame DSLR (Nikon D750) for photography/videography along with a general purpose zoom lens (Nikon 28-300 mm), a wide-angle fisheye lens (Samyang 8mm), spare batteries and a circular polarizer.

I carried the lot in a Lowepro toploader Zoom 55 bag, slung crosswise from the shoulder and clipped with a carabiner to one of my backpack's straps, to prevent it swinging around. It all weighed 2.75 kg (6 lbs). This was quite heavy and cumbersome to lug around, which got me thinking about the perfect small and light camera for trekking.

DSLR gear used during the trek

The boundary conditions

A small sensor camera, obviously, cannot have the image quality and performance of a full-frame DSLR. Hence, one needs to rein in one's expectations regarding image quality and the types of shots that can be taken -

1. I won't pixel-peep at 100 % (i won't :)). Viewing at up to 4k resolution (8 MP) seems reasonable.
2. No fast/accurate tracking and burst shots of flying birds/aircraft.
3. No close-up shots of birds up in the trees or of wildlife further away.
4. No 360x180 equirectangular panoramas.
5. Telephoto zoom range may be limited, so not much latitude for cropping.
6. Subjects can be wide landscapes, people, wildlife that is close, horizontal (not equirectangular) panoramas, maybe some macro.

The ideal camera for trekking

1. Form Factor of a (large) compact camera, not that of a bridge/DSLR camera, to allow it to be stowed in the thigh pocket of trekking pants. Not larger than 5x3x2 inches (127x76x50mm).
2. Light Weight, below 400 g (14 oz).
3. Fully Self Contained (including lens cap).
4. Full Manual controls for stills and video.
5. Image Quality should look good at 4k (3840x2160, 8 MP) resolution. Hence, it requires a sensor size large enough to give this quality while at the same time keeping the camera compact enough.
6. Raw image format.
7. Good Dynamic Range (12 eV).
8. Fully Foldable Zoom Lens with (35mm equivalent) focal length range of 25-300mm. This allows taking wide (though not ultra wide) landscape shots at one end to close-ups of nearby wildlife at the other.
9. As small lenses usually don't go down to narrow apertures (like f/22), a built-in Neutral Density (ND) filter would be a plus.
10. As small sensors have good image quality only near base ISO, the lens should have a wide aperture fully open (f/2.8 or wider) through out its zoom range, to allow low ISOs to be used when light is low.
11. Autofocus (AF) and Shot-to-Shot times should not be too slow.
12. Viewfinder for shooting under bright sunlight and for more stable video panning. I prefer an Optical Viewfinder (OVF).
13. Built-in xenon (not LED) Flash.
14. Good battery life.
15. Able to shoot Video at least up to 1080p60.

Recommendations

There is no camera that meets all the above criteria as of now (early 2016). The smallest 1/2.3" and 1/1.7" sensor cameras don't have the required image quality (purely my opinion). The most promising ones with respect to quality/performance vs size are the cameras using the Sony 1" 20 MP sensor. The ones which tick most of the boxes are the Canon G7X and the Sony RX100, though the long end of their lenses fall quite a bit short. If one relaxes the size limitations to gain more telephoto range then one can consider the Panasonic FZ1000 or the Canon G3X though these definitely won't fit into a pant pocket, so not something that i, personally, would consider. If one wants to trade image quality vs size, there's the 4/3 sensor Panasonic LX100, though it doesn't have a built-in flash.

Update, Nov 2016:
The most promising camera seems to be the Panasonic DMC-ZS100 (aka DMC-TZ100).