My understanding is no unless by "moving" you mean demolishing the old city and starting from scratch.
We have a situation where we are hemmed in on one side by Mos Entha and the old battleground to the north so we lose quite a chunk of land to both structures when we asked about moving the city eastwards we were told that once the city hall goes down the city no longer exists and there was no guarantee we would be able to re-place it at its current rank.