I'm so glad D and Gayle are helping you =) You're in excellent hands! They have been helping me with my Tugger and I couldn't be happier =)
I do know how you feel, I had to leave Tugger just after his diagnosis. It was stressful! I was only gone about half the time you'll be gone and I was nervous! I highly recommend making sure you have instructions for hypo situations. Highlighted even. Maybe even leave the web address for this forum and instructions on where to go to get help if they need it. Not sure if a pet hotel would have internet access or not, but it's worth a try.
Remember that boarding will be stressful and will likely elevate her numbers a bit but even still, you are better sticking with the 1u because at the very least you'll worry less about hypo. The stress of boarding combined with the dry food will probably keep her numbers up there. Even prescription diabetes kibble is high in carbs, it's worthless crap but for right now I wouldn't change it. Because again, it will probably help keep her numbers up and if it were me I'd worry less if my kitty rode a bit higher while I'm not there to watch. But I'd look into making a change to all canned low carb once you get home and settle in.
I'd also suggest, if at all possible, to have them call you or you call them to get a daily rundown on her numbers or make them use the ss online so you can access it from where you are. This way if something does come up, you can come here and ask for help (assuming you will have internet access)
Finally, I would change the instructions regarding feeding to say that she should be fed after BG test but prior to shot. I say this because if Vesta refuses her food you probably don't want them giving her shot (this is something I see a lot but get someone else to confirm my thoughts) or you might want them to sprinkle some dust from her freeze dried chicken on her food to convince her to eat before her shot. You always want food on board with the shot, so unless you know for sure that she will eat no matter what, I'd change it. Only you know Vesta and her habits though. My guy would refuse food in a boarding situation, even though he loooooves food, the stress would steal his appetite. He prefers someone hanging around when he eats so he doesn't eat if I leave him home alone for too long.
Hope all goes well for you and Vesta (love her name!)