I don't have much to add, except that no matter how much or little you spend, a larger sensor will pretty much always pick up a better low-light image. You may be able to get a semi-usable image from the light of a campfire, but the video will be very noisy. Additionally, if the campfire is in view, the camera may have trouble figuring out if it should adjust the image so the fire looks good, or the faces. Usually it will pick the fire because it can't see/understand the faces.
In terms of pocket size, do you mean literally pocket? Would something like a Sony NEX camera with a short pancake lens qualify?