How to get out of the house with Formula-fed baby?

[Cinai2]

My DS is 11 days old and I’m getting ready to prepare for leaving the house with him beyond trips to the coffee shop next door. Unfortunately I have insufficient milk supply and need to feed Formula, midwives are not optimistic that I’ll ever be able to produce more than 25% although I currently do what I can to boost supply (at the moment he only gets a max of 10% from breastfeeding at each feed).

How do people manage to feed on the go if baby is formula-fed? Do I just take formula with me and ask coffee shops or pubs along the way for some boiled water when I need to prepare a bottle? Are they usually happy to help, and is it safe (at home I always fill the kettle with fresh water and avoid re-boiling). Or do I need to get ready-mixed bottles of formula?

15% weight loss is absolutely not normal. My then EBF baby lost that and was very unwell and hospitalised, we were on a feeding plan and as I couldn't pump enough he had to have formula because he was starving and they needed to know how much he'd had. There wasn't much support for breastfeeding, but as it clearly wasn't going well at that point I was quite relieved to use mainly formula and just supplement breast milk for comfort.

It's not what OP asked, but I wouldn't want people thinking 15% is normal.