I had to evacuate 43 chickens (8 mature hens and 35 juvenile FR meat birds) last summer due to a forrest fire. I can say the move was stressful for everyone but after 9 days of being housed in my sister-in-law's garage and attached dog run, we moved the hens back home and the FRs to a "foster" home until the weather changed and brought lots of rain. Then the FRs came back home as well.
Egg production was down for the time we were at my sister-in-laws, but we didn't lose any of our birds during the evacuation. I did have one Jersey Giant hen who I was treating for sour crop in a separate crate in the cool of the garage when we got the manditory evacuation notice. She had to be piled in with the rest of the birds, and while I tried to continue to treat her during the evacuation, I couldn't give her as much personal attention. She died about a week after we got home. Who knows if she would have died anyway, but the stress couldn't have helped.
I agree with the person who posted above that this will add some stress to your hens, but if you are moving them from one well built, familiar coop to another, and they are used to being handled, they will probably adjust OK, but your egg production will probably suffer.