DS is now 5 but I used to fill 6 sterilised bottles with boiling water & use them over the course of the next day.
I had a little pot from avent that I also sterilised & put up to 3 lots of formula into it in separated sections.
Either I would use the bottle warm if the water was still warm enough or I would heat it up in a microwave and give it a good shake to avoid hot spots in the milk. (Obv not recommended by most books, hv's etc).
I never used boiling water to make the formula unless I did a bottle to take out with me to a group and I gauged after a while that it would be warm enough to give him a feed without warming it up again. I had a bag with insulated pockets.
I did it this way (boiled cooled water) simply because a good friend had her ds 2 weeks after me & he was in special care for a while & they made the formula up this way. If they didn't see the need for boiling water with tiny poorly babies I couldn't honestly see it was an issue.
Obviously you have to make your own mind up but I couldn't imagine having to start boiling the kettle when ds was already hungry/started crying.
It's a minefield though - bad to leave dc to cry if you want to put them in a routine but ok to do the same thing if it takes ages to make a bottle.
Whatever you do, honestly, someone will pull a face. Ds loves his milk, slept well, v chilled as was I (mostly!). Not too different now tbh.
Congratulations on your new baby xx