I would suggest posting on the cactus/succulent forum as well, because someone there is more likely to have experience with this kind of thing and you don't want to mess up! I also wonder if you should recruit more people to help, just to support things if they show signs of overbalancing, falling apart, etc.

Yes, I agree. Post this on the cactus and succulent forum (since your jade is a succulent). It's much less "busy" there and you'll also find more people that can give you good advice.

Jades are almost indestructible. They almost never die unless overwatered and then rot or they get frozen. I am assuming there is more than 1 main stalk. If you can get them apart and pot them up seperatly that would work. My mom had numerous of these and since they get top heavy branches would sometimes break off. Let those callous over for a few days and then just stick in soil. They will root. No water until you see roots, otherwise they will rot.
You will most likely have a few branches that will break off. You could use a wooden barrel or perhaps some sort of big plastic storage container tub, but put a few holes in the bottom first. It could probably use a top dressing of new soil also. If it currently is in a 14 inch going to a 25-30 could kill it as there would be a tendency to overwater. You should be able to find a 20 inch at any big box store or walmart type. Jades have small root balls which makes then top heavy. Normally you only pot up 1 size but in this case I think a 20 is fine.
I would search the faq's on the cacti forum also.

Hi all,

Just wanted to comment on rooting jade cuttings (since it was mentioned in the previous post). I've read time and time again that if you root them in soil you should NOT water them until roots form, and that does make complete sense. However, from experience, I now know that watering the soil BEFORE the roots form is not a definite for causing root rot. I pruned my big jade in December and left my cuttings out for a while in nothing...just layed them on top of a radiator(I was told and I read on here that they will root that way if left in bright indirect light). Anyway, after about a month or 2, aerial roots started to form at the tips, but nothing at the bottom. Not only that, but the leaves actually started to wilt and looked "prune-like". So I knew they needed water. I rooted the ones that looked the worst in water (and that's not something I'd completely recommend...they root easily that way but the transition to soil isn't easy). I rooted the other cuttings in fast-draining coarse soil mix, and I watered them pretty much on a weekly basis (yes, even in the winter...but just a little water each week). I checked them the other day and they had pretty hefty rootballs! So there was no root rot and the cuttings look completely healthy and full now.

Just wanted to discuss my experience since I know there are so many who are against watering unrooted cuttings. My opinion is that if you are planning on rooting with soil, do not water and wait to see if you get roots (which you probably will if the season is right). But if the leaves start to wilt, they are telling you they need water, and you have nothing to lose by watering the soil. Just my opinion :-)

By the way, I agree about getting a 20" pot. I have my jade in an 18" pot and it's probably nowhere as big as yours (2 feet tall from soil line to top and the foliage spans a little less than 2 feet wide).

Gabi