The convention takes place at The Garrison Hotel. When booking it is always advisable to ring the hotel rather than rely on the website online booking. Make sure you state that it is for Furnace Games Convention.
The room price for the Garrison Hotel is £70 per night inclusive of breakfast.
There are a varied range of hotels in reasonably close proximity to The Garrison.
A good alternative are local AirBnBs. Here’s a link to get you started: