Most airfields have the options of going 24 hours, subject to approval from the relevant authorities and the inevitable complaints from locals.
However as coventry has done it before they would have no problem doing it again i shouldn't think, BUT theres no point going 24 hours if you havn't got traffic, thats alot of money being wasted no staff sitting around for one aircraft. It would be more likely to start doing short hours and build up from there if and when traffic permits.