It's pretty much just the UK where you are told to make each bottle as you go along, don't store and use water over 70 degrees. I once remember reading a post from a woman in France and she said they were told to make their's with cold mineral water - a big no no in the UK! So go with what's the norm in your country. The UK has a big drive to discourage FF at the mo so a lot of our very stringent rules are probably a lot to do with that.
Windmills - the official reason for using cooled boiled water is to kill any bugs in the powder, not to sterilise the water. This is because powdered milk is not sterile and when you go into it to get the scoop out germs can be passed into it. However, washing your hands etc can do a lot to minimise this risk completely. You can give a baby regular tap water after 6 months but are supposed to continue using cooled boiled water over 70 degrees for as long as you use powdered milk for this reason.
And yes, I pre make bottles (not all the time though) and have made them up with water under 70 degrees occasionally as does pretty much every FF'er I know and never had any problems. As one OP said, just follow basic rules of hygiene and don't leave a bottle for milk sitting around in the sun for hours (as if you would) and feed it to your LO and you'll be fine!