Racing indoors over winter does seem appealing though believe the catchment area of members is quite widespread. So for many to get there at say 7pm would be quite a struggle.
It might be worth starting a poll to ascertain how many members could and would actually attend an indoor TORCH series. The roads are fortunately a lot more empty on Sunday mornings.
Alternatively what about starting a thread asking for some suggestions on how to cope with racing at TORCH over winter + in the rain. It might be a lot easier to make a few modifications to your car and to buy a few waterproofs then it would be to set up an indoor series.
What do other clubs do on rainy cold days?