Riders who currently double up/down will lose at least half their pay packet probably more.
They will have 3 options :
Try find a team abroad (will be difficult as most foreign teams signed up)
Ask Championship team for significantly higher wage
Retire and get a job out of the sport.
Option 2 or 3 will have big impact to Championship
Discovery WB had 100 staff on site each GP, which was probably well over the top, but involved constructing the pits and that stage in middle etc, presume all that will be gone now.
Who ever takes it on is taking a massive risk, I'm all for new tracks but this is going to be very difficult to get a regular fan base crowd. Its not that close to Northampton.