NPAS are in a number of places like that - Carr Gate Wakefield for the FORMER West Yorkshire aircraft for a start.
But NPAS is not a police force resource.... well not anymore. It is NPAS. So while it may stay where is is already placed it will not be necessarily welcome taking space and creating complaints at a previously unused location.
Airfields, particularly underused RAF sites are a good mix of wide open spaces and aviation knowledge on the part of the host. Most traffic units I am aware of are cramped in pure aviation terms and the public have a horrid habit of buying houses right next door.