I think it comes down to the fact that the patriot (and any modern vehicle) is heavily controlled by computers. That even if you had the unlimited funds to swap hardware over, you would hit a HUGE road block with the software. Most people here (and my experience with 10 years of car tuning) the dealers are impossible to get to install software that didn't come with the vehicle originally. Too much liability (and often, you'll get the response that they cannot, because they don't know how and are not willing to learn) if you take it to a shop that will be able to do a custom program, your costs would be astronomical... at that point, regardless of your desires, you would be much better off buying a 4x4 vs doing the swap. Since it is available.
NOW if you were looking to do a solid axle swap. that's a different story, since you cannot just go out and buy one. If you're willing to spend the money I'm sure it can be done, but you'll have spend gobs and gobs of cash. Since you cannot use any part of the existing drive train. Unlike a liberty that was still rear wheel drive and had a correctly placed transmission, and you are just working on the front end. The patriot would need a new engine (or at least re-position the engine.) a new transmission, new drive lines, new break systems, transfer case, axles, suspension, etc. and software would have to be a custom tune job anyways since there is nothing available from the dealer. There i would buy a pat Super cheap that had a blown engine. And use that as a base. I would see if I couldn't put the new 3.2l v6 in there for kicks and giggles.