Dedicated bogger
If it is just for offroad on your farm use, find you an older good running 4wd truck now make a BOGGER. Being strictly offroad, you can go nuts with it, and go way beyond street tires. Big lift kit, then install the largest widest gnarliest wheels and tires you can. You've seen the big singles they use on farm spreader trucks, the "illegal for road use" size? Them babies. In fact I have had the thought one of those spreader trucks slightly modified would be slick for firewood, if you could get the rounds up into the back of it. Figure out how to open up the back some and use the built in conveyor for unloading....somehow....
Cheapest conversion most guys do to a pickup is a set of army truck rockwells, front and rear axles and then whatever wheels and tires. You will get from point A to B with that conversion.
I see deals sometimes on CL where guys have already done all the work, built nice trucks with the rockwells, then for some reason sell them or have to sell them for about what the parts cost them. Usually something like they built them as a toy, then a new baby on the way and they need something more practical, like a minivan...heh.
For that matter, you can get a deuce for what they want for one of them little high end ATVs or a used "normal" pickup. A lot of them come with a built in heavy duty winch. Drive to where you can, now winch out the log.
For real small and ability to get into the woods and back out, including dragging out some logs, check out rokon.com. That's the smallest most maneuverable offroad thing I have ever seen. It's basically an inline 2wd compact tractor. It just looks like a bike. That and a log arch could work.
After that, you can always go retro and use a horse/ox/mule/donkey.