Connecticuts problem is not that the whole state is not on P25, its that they run on frequencies from 30mhz all the way through 900 mhz. Police station A is on 30 mhz, police station B is on 800mhz, then this fire department is on 150mhz and that ambulance on 450 mhz.
Check out Groton CT.
Groton Town Police are on 800mhz, conventional, analog.
Groton City Police (within Groton, surrounded by the Town Police) are on VHF (150mhz).
Groton Long Point Police (a 'boro' within the Town of Groton) are on UHF R2 (450mhz).
The local police must deal with the Navy Police at the SubBase, wholly within Groton, operating on a P25 Phase I Trunked UHF R1 system (380mhz)
Also within Groton are the State Police covering I-95 and providing law enforcement to some schools in Groton, operating on an 800mhz SmartZone (3600 baud) trunked system, with digital voice.
... never mind their immediate mutual aid for pursuits and K-9 operate on 800 (9600 baud) P25 Trunked ...
The only way they can all effectively communicate is dispatch to dispatch on the LowBand (45mhz) hotline.
You want the state to get on band or system? Try getting a single municipal area law enforcement to get one single way to communicate.