Okay, this is what I finally did.

I got tired of worrying about the load in that room so I picked up some 12-2 (about 250 feet (waaay overkill on length)), about 80' of conduit pipe and corners, and two 20A circuit breakers, along with two 15A plugs and associated mounting hardware. Ran me just north of a single bill.

I then proceeded to dig a trench (shhh, about 4" to 8" in places) to run my line. I had originally planned on bringing in another 20A of power to the room, but when I realized that I had a freaky amount of wiring I picked up the other 20A circuit breaker.

I installed the wire from the external 200A drop box, ran it clear around the house and through the wall. Installed everything inside to code (which implies that the exterior was done somewhat less than code, but it was all to code).

Then the first real test. I tied in the appropriate lines for single phase power to the room (I almost purchased the dual pole circuit, whew). The second real test was flipping the switch. The third test was unplugging the extension cords running to the room and reconnecting it to the newly installed plugs. I put in a four place plate that houses two 2xplug sets. A single 20A circuit running to both.

Where I messed up. Should have went ahead and ponied up for the 20A plugs. I didn't need 20A plugs, but since everything else is wired for 20A to include the circuit breakers I've actually created a weak link in the system at the plug in point. I did get the best rated 15A socket sets that they had... but still.

Now I've got a total of 40A available to the room above and beyond the stock 15 that the room was wired for.

I'm out about one note, about four hours, and I'd say about half a cup of A- (I sliced into my finger rather deeply and it bled for about 15 minutes before God's bandaid was able to take affect).

Relax guys, I didn't get any of the blood into the tank (didn't want the massive amounts of iron in me to mess up my water parameters).