I think that it depends on the baby.
Ds1 had SMA with no problems. Ds2 didn't do well on it, green poo, constipation, I switched him to Aptimal after 4 weeks and he was much better but still has reflux and gets quite uncomfortable.
I was breastfeeding but after a few days of ds feeding and suckling constantly I was in pain and couldn't bear it anymore, dh ended up driving around at midnight trying to find a shop to buy formula as I was in tears with the pain, I wish I'd had some emergency formula in.
I did go back to breastfeeding and also expressed milk for a couple of weeks before permanently switching to formula, but we were lucky to find a shop open that night.
With regards to making the bottles, I wash and steam sterilise them. Initially we made a couple up at a time I now make a days worth in advance.
I know it's not recommended but it works fine for us and I feel there's more chance of me making an error making them up in the middle of the night.
I boil a kettle 1.5litres, then let it cool for 30 minutes, the water must be above 70 degrees to kill bacteria in the powder as it's not sterile. I make the bottles and flash cool them in cold water before refrigerating.
If we go out I use a cool bag with an ice pack or bring empty sterilised bottles and ready made cartons.