I am being asked by the regulars of the festival I run in the Summer for a Winter branch out. We need somewhere fairly central for 150+ people, a stage for live bands and either with a hotel attached or cheap(ish) ones nearby.
Celtic Manor near Newport, South Wales http://www.celtic-manor.com/conference
Celtic Manor is quite pricy
Do you mean central like in The Midlands? I’m guessing it’s an indoor venue you’re seeking as it’s winter? How about Rock City in Nottingham? There are plenty of budget hotels nearby.
Might be a bit bigger than you’re looking for but The Leamington Assembly in Leamington Spa hosts a lot of gigs and there are a fair few hotels in the area which might have a fair amount of availability outside of the main tourist season.
Also The Forum, Tunbridge Wells and the Bear Pit in Stratford Upon Avon also have plenty of hotels, B&Bs nearby and good transport links.