An option to Pack up and Leave an area would be nice especially in the early game if you spawn out in the middle of nowhere and want to move closer to the center or vice versa
The ability should be a low level research possible right after marketplace but a very expensive an slow process
After selecting to move your city it will stop all production of basic and advance resources as your populace will begin tearing down your city and preparing for the move.
Depending on the size of the city the break down could last several hours or days.
After the city is broken down your people will carry it to your new location the trip will be slow and some population will die from exhaustion, exposure, and other dangers of moving.
When your city is at the final destination it will begin to rebuild which will also take several hours or days to finish.
The cons of moving
0 income from the time of demo till completion is finished
You can lose 10-30% of your population depending on city size and distance traveled (represented in random loss of structure levels)
It will cost a lot of gold, your people wont work for free
You may have to set your taxes high for a while to save up enough gold further reducing your income
Pros
You can move your city for what ever reason