I did this for my best friend's wedding many years ago. I was living in Oklahoma at the time and she lived in Phoenix (coincidence!) I had two very small children at the time and could only be away from home for a couple of days. I flew out on Friday, wedding was on Saturday in the early afternoon, and I flew home the same evening. Here's how I did it;
1. Pre-made icing flowers out of royal icing and packed them, nestled in cotton, in plastic containers. Made lots of extra in case of breakage.
2. Pre-made buttercream and packed it in a couple of large plastic containers. Also packed all of the supplies I could think that I might need from start to finish, even my baking pans. The only other thing besides supplies that I had in my ginormous suitcase was my dress for the wedding..lol!
3. Arrived early on Friday morning, went straight to the bride's mother's home, and started baking. I had given her a list of ingredients to have on hand for me, so I didn't need to shop on the way. Cakes were baked and iced by dinnertime. Took a break for dinner and then decorated that night.
4. Transported cake to venue and set it up on Saturday morning. Had nice wedding, ate cake, rushed to the airport.
5. Flew home and collapsed from exhaustion. :) But the cake looked great!
Good luck to you and I hope it all turns out okay!