This is incredibly distressing to me

Boarding works well for dogs because they’re social animals and they get to play and interact with all the other dogs. Kitties definitely do better in their own homes. I travel quite often…well, I used to…but anyway, I have Petlibro automatic feeders for dry food which I can schedule and/or activate with my phone, I have cameras to keep an eye on them, I turned my deck into a catio with a microchip-activated cat flap door for access. If I’m gone more than a day or two I have my cat sitter come and give them their wet food once per day. Apollo, my big orange boy, hides from her when she comes, but my little tabby girl Mae likes her and they play with the laser pointer when she comes over.
All that being said, cats as a general rule live in the here and now, and they don’t hold grudges. I’m sure she will be extremely unhappy, but she will forgive you and will probably be back to normal in no time once you are both together again. Hopefully you will have a day or so to spend with her before you have to go back to work or whatever.