I would definitely make sure she will take a bottle before you leave. Know she will eat before you’re gone. My LO is seven weeks and I sparingly use bottles, but I use the Dr brown premie nipple, slowest flow that most mimics breast.
Size x is meant more like breast as they control how much. Personally mam worked for us but orginally tried tomee tipee but wouldn't take
My LG is also 5 months. She’s ok on Dr. Brown nipple size 1. I’m now thinking of giving size 2 a try, but except her being super active (on the breast or bottle), she has no issues with it. But definitely try at least for feeding her a whole day with the bottle routine (and with the person who is going to care for her) before you go to make sure you don’t have to come back in the middle of your plans. It’s difficult and I feel your pain as I’m preparing to leave for a week of work trip!
Following because my EBF 8 month old won't take the bottle 🙃