I'm noticing some posts about root pruning.  I assume these are about maintaining fig trees in pots, rather than in the ground.  Are there any instructions out there about how to do this?  How much root to cut off?  Best soil for potted figs?  etc. 

Also, if I root prune for a year, to keep my fig at a pot-able size, can I later plant it out in the garden (for example next year)?  Or is it, once you start root pruning, the tree will remain dwarfed or otherwise unsuitable for the garden?

I have a real nice Lattarula (Italian Honey?) fig in a pot that I'd like to keep but I may have nowhere in the garden to plant it until next year.

The might help you.

http://www.figtrees.net
http://www.figtrees.net/care.html

Ron, i posted some pictures under "Root Pruneing Pictures Today"
i dont follow a set of instructions but prune to the needs i feel of the pot its growing in at the time. I posted pictures just as a sorta look and see what i did to maybe give people an idea of where to start that are not familar. In my case with my pots they grow in i use a sharp tree pruning saw its easier for me to cut the roots and thru the soil thats been in pot for 3 years. I cut about 35% off the one i showed is my best guess and poked around afterward with a long screwdriver to loosen it up a little further. I cut a few inches off the very bottom  as well as cutting the sides and cutting some wedges all around you may notcie in pics. I then measured with a tape measure the height to get an idea of how much new soil to put in pot to bring the plant up to a level im comfortable with. I used fertilome upm mix, there are many different ones out there and some amend there soil even further like adding perlite, lime, compost, etc.
I will continue to root prune every 3 years , each time looking at the root system to see how much I think needs to be trimmed, the roots always keep growing and so does the tree itself.


You asked
Or is it, once you start root pruning, the tree will remain dwarfed or otherwise unsuitable for the garden.
 
The tree will continue to grow and will be suitable for the garden as long as you properly take care of it in the winter months once in ground which is different than growing in pots.
What i do in root pruning is not written in stone but just to give an idea to some, many others have there own way of doing things ands thats how it should be. I hope this helps some for you.
Nice thing about fig plants is are they are pretty resilient for the most part .


 

What is the smallest size pot you can reasonably maintain a fruiting fig tree in, over the years?

Not sure,
 my guess would be minimum 5 gallon .
Just a guess.