Re: what to sell/storage
I had a similar problem but everything changed when I realised I could get a bike into the loft. Wheels off and seat out and with a bit of care they go in - and my loft hatch is small/medium sized.
So I have a few in the "shed" and easily accessible but rotate with season/need/fancy a change.
No more bikes in every corner and in the way.
Obviously that wouldn't work for everyone but perhaps useful to you or others.
If you do have a loft or something similar and still want to cull, you could keep frames and swap parts. So for example DBR and Torus, parts mostly interchangeable (?), sell off whatever's effectively duplicated between the two and keep one frame, seatpost etc in the loft and if next year you fancy a change you can swap over. If you find you never do swap, then you could sell the unused frame.