Timber framing uses dry wood as well, slightly different techniques but in the softwoods and some of the hardwoods its is not all that harder to work dry than green and in some ways easier. It depends on the tradition and location as to the exact process and technique, some preferred dry timbers, some green, some something between.
In US farm country it was common to fell the trees in late fall/early winter after the harvest was all taken care of and then leave the trees where they dropped until the ground froze. After the ground froze you haul them to the build site, much easier to drag logs on hard frozen ground than on soft wet ground. Then you would forget about them until after the spring planting is taken care of and build in the summer. Those big timbers would be far from dry but they will have lost a fair amount of weight and will be more stable which makes everything easier.
I can only speak to my own experience of doing this professionally in northern climes without power tools for ~5 years, but both of your suggestions are foreign to me. I take this as a nice reminder that there is lots of regional variation to this craft around the world, which isn't surprising.
Even then, building a barn with dried pine or hemlock is much more tedious and incurs many more trips to the sharpening wheel. It is in no way easier.
The joints used in dried are dictated by the operations which are easier to do in dry wood and are not influenced by what the wood will do as it dries. Dried you get to use a saw with considerably less kerf and a thinner plate, augers can be more aggressive and take better advantage of lead screw and spurs. Chisel work will be a bit slower when chopping across the grain but not harder and if it incurs many more trips to the sharpening stone you are most likely trying to chop that mortise as you would in green wood.
I read a biography of the earthmoving equipment maker R.G. Le Tourneau, and it was really eye-opening how much this was a thing before mechanized equipment was readily available. A lot of moving was put off until winter because it was so much easier to drag logs, boulders, buildings, etc. over ice than over thawed ground.
Or waiting for things to freeze real good so you can dig the kind of hole or trench that would make HN clutch its pearls or simplify de-watering problems.
I’ve never tried to dig in frozen ground - isn’t that going to require blasting equipment or techniques closer to mining? (Heavy pneumatic jackhammers)
Well, in the era we're discussing, there wouldn't be jackhammers. Mainly a bunch of guys with pickaxes.
Generally you just build a fire on the ground you want to dig up, possibly throw in some good sized stones to hold the heat longer. If the frost is deep might turn it all over once the flames have died down and bury those coals and stones so their heat is more contained and not just going up into the air, or have a second fire after you have dug out the thawed soil.