South Oxon Archery Club hires a hall 2 evenings a week during the colder months, I believe, rather that practice in the dark.
The people I met there last weekend said they were already using it, but I've not been there - I'm told it's in Maiden Erleigh, Whitley or somewhere thereabouts. You might like to give Fred or Bryan a call - their details can be found at
this page.
Reading Archers might be able to help, too.
Matt