Bottle feeding breast milk

Baby is 1 month old, EBF. We will be out at an important event next weekend so I’d like to bring a bottle of my milk *just in case* I can’t get away to nurse.

I’m expecting there not to be a way to warm the bottle. Should I bring fridge-temp milk in an insulated bag and just give it to her like that? Or should I warm the milk *before* we leave home? Will the insulated bag keep it warm/fresh enough for 3 hours?

This is probably such a dumb question 🙈 Any tips on feeding a breastfed baby while away from home are appreciated!!