Since you have some advance notice you are at an advantage. Don't feed for 24 hours before, or 24 hours after the cut, feed lightly for the next week. Less food means less waste produced, minimizing any ammonia or nitrite spikes.
If you are not going to be around floating the cleaned media is your best bet. If you will be around, take a plastic cup, a beer cup works great, and punch some holes in the bottom. Clip this to the inside of the tank, so it is filled with water. Place your media in it, and every hour or so pour some tank water through it. This will work pretty much the same as your filter.
Floating warm water in bottles is the best idea to keep the temperature up, if it is hot like it is by me the air will be off, and there is no need for this.