I'm just here waiting for people to hunt out some inventive TP runs to get around the 5 day min!
Here's my imaginary suggestion.
NCL>LHR>EDI
Hire Car, drive home to NCL.
Drive back to EDI next weekend
EDI>LHR>NCL
320TPs, 4,000 Avios - might be doable for a reasonable price if you were trying to top back up to Gold!