I was recently gone for 5 weeks and I just waited until I got back. I've heard of people not paying their bill for 2 or 3 months. Apparently Korea is not that hard nosed about it. I probably wouldn't go that long but everything was still on for me after 5 weeks.
I think paying from a non-Korean bank account would be dang near impossible, better to just keep it simple and leave some money on your Korean bank account to cover it. What you've outlined would be a neat system, but this is a country where you can't even buy stuff off Gmarket with a foreign credit card...I wouldn't bet on KEPCO having such a system....leave some money in your Korean bank account, set up automatic payment and forget about the whole thing and enjoy your trip :D
- Set up direct payment through KEPCO. This is what most Koreans do, I believe.
You should be able to do this through your bank. I took my most recent bill, passport/ARC (whichever you used to set up the bank account) and my bank book to set it up and now it just automatically comes out of my account. :)