Going away for three days and might lose gains:(

Tomorrow I'm flying to Auckland for a concert and I'll be gone for three days and I don't want to lose my gains!? What should I do!? It's going to be hard because I'm in a crappy hotel with no stove ect so I need to buy my own food (most likely takeaways) so what should I eat? and should I do quick 5/10 minute exercises in the morning like pushups ect?