Leaving our almost 3 year old daughter for 2 nights and 1 day

I’m absolutely petrified. We have 3 kids- a 5 year old, an almost 3 year old, and a newborn. Our ~3 year old has been very very difficult since we had our newborn. Im going to an event with my husband for 2 nights and we’re leaving our son and daughter with grandma. My son is excited. My daughter is going to go bonkers and I’m steeped in guilt. This is not a must trip. It’s somewhat optional. My husband has slept in her bed basically since the baby was born because she’s reverted back to needing it. Our baby’s 7 weeks old now so she’s gotten pretty used to it. I basically just need advice and reassurance that we aren’t going to mess her up especially since she’s not having an easy time (increased tantrums- like majorly) and just an overall difficult time adjusting. She loves her grandma but when she stayed over at other-grandma (whom she also loves), she cried and screamed for 25 minutes before bed. I’m so so nervous.