Had further thoughts on this on my ride home in the dark.........
What about combine with a night ride.
Get to GT a couple of hours before dark and push klunkers to the top of spooky wood. Then either as a time trial or just mass descent go down spooky to the timber track, go along that and past the foot of the spooky climb then onto Blue Velvet then Berm Baby Berm then across the carpark and down the road to the Squirrel carpark. Downhill most of the way and not beyond the capabilities of a rubbish braked road derived klunker. Do it as one continuous non stop run like the Repack itself.
By then darkness will have fallen and you can put your klunkers away and drag out your proper nightride mtb's. Plus night ride cowards like me can bail and head home.