Breastmilk in straw cup or bottle?

Al

My babe is 8 months old and after a rough start with breastfeeding and exclusive pumping hasn’t had a bottle since about 4 months. Now that he’s eating solids he drinks water out of a straw cup. So we are going to Napa in a week and I’m not sure what to put my pumped milk in, the bottle or the straw cup?