WOW! Let me shake those off!
Current status is that it starts, runs smooth for a few minutes, then it starts idling rough. Correct? Or will it not stay running and it dies?
I know you have been frustrated by this.... Just goes to show, no good deed go unpunished! You change your spark plugs, (good deed), now you are ready to drive it off of a cliff. Hang in there....
I know some the things listed below you have already tried. I ask you do it again.... sometimes it takes two or three times of doing the same thing to figure it out.
Did you change all of the plug wires? I see where you just changed #1....
Recheck and make sure you have the wires installed correctly. (I know you are rolling eyes), but mistakes happen and sometime it is hard to find your own mistake. Like Proof reading your own documents.... Tell us what cylinders are connected to what coil. Remember, this all started with the spark plug change.
Which brings up another thought. It is possible that one of your new plugs is damaged, maybe cracked. (Before you bought them some bonehead might have dropped one and put it back in the package). That could cause a misfire that you would never see. Especially after it gets hot.... might work ok cold, then when it heats up it shorts to the head. Just another possibility. I've been a bone head before and dropped and cracked at least one in my life.
From what I've read, you think you have the problem narrowed down to the #1 cylinder, right? If the car will run, and is idling rough, loosen the sparkplug at the coil so you can remove it with a pair of insulated pliers. With the car running, (and missing), pull the #1 plug off of the coil. If the engine miss remains the same, and does not get worse, and you see spark coming from the coil, you have narrowed it down to that cylinder. Since you changed the wire, you can rule that out. Pull the #1 plug. inspect it. Is it wet or dry? If it is wet then either the spark is not getting there at the right time, or is most likely not getting there at all. Check the the plug gap, check for damage and hair line cracks.... get a new one or heck put an old one back in.
If it is dry, that would mean no fuel. Put all the plugs and wires back together. Start it back up, idling rough still? Start proding the injector harness wire that feeds #1. see if by gently jiggling or moving the harnes the engine smooths out.
If you remove the plug from the coil and the idle gets worse.... all of the above might not pan out. But a cracked plug could cause some very strange issues.....