We had everything but a jack- all the tools we needed to change a tail wheel on our Tundra were a set of pliers, a 3/4" wrench to pull the axle, and a pair of 7/16" sockets (and drive handles) to split the rims. Oh yeah - a source of compressed air to inflate the tube as well. Fortunately, the mountain ranch resort where we had landed for the evening was self-sufficient - they had to be, since the only way in or out is by air, or horse. So they had a bottle jack and small piece of plywood to keep it from sinking into the soil.
The tail wheel wasn't actually flat - but it was getting pretty worn from lots of landing practice, so since we had a spare, and a beautiful afternoon (the flying was done for the day due to winds), we figured...why not? The total task took about half an hour.
So when you think about putting together a tool kit for an "away mission", think about the tasks you might need to do in the field. A complete tool kit might sound good, but it can be heavy - so think your way through a project, and visualize what you will need. I don't carry a complete wrench set - just the wrenches that fit the fasteners I am going to work on. If we hadn't had the bottle jack, we would have propped up the tail by hand. Tire inflation? How about a bicycle pump?
You probably won't be pulling a jug - but tires, leaks, and replacing missing screws are going to be high on your list. So do a little mental exercise on what you might need to accomplish - and then take just what you need.