If the back country has trees it is easy to raise the front end using your winch enough to change, repair or work on the front end. I can do the same on the rear end with my rear winch but most machines don't have one.
You can also use a cut tree or dead fall as a lever to raise the front or rear end and block up the machine on either axle. You can also build a small ramp to drive up, out of rocks, dead fall etc. block up the axle and remove the ramp material and drive off after the repair. I carry a small axe, small bow saw and or a chain saw if exploring an older seismic line. I also carry a small come along that could be used to raise the machine using a tree for support.
I carry an air compressor or hand pump, a small patch kit and some small ratchet straps along with a long screw driver and other tools. My most recent purchase has been "tire ject" which can be poured into the tire after removing the valve stem and air back up. I think there is a thread on here about different products. The good news is that quadding since the mid 90"s we have had only one machine get a flat that we needed to bring in a spare wheel for. We usually quad in the Alberta foothills (crown land) where there are some sharp rocks, lots of dead fall and some muskegs. Our day trips can be 60 miles long so a long way from the vehicle or help.