Hi Eric,
I too shall be going via the M74 and A66. There were long term roadworks on the A66 last October, may be completed now. Its the big upgrade near Scotch Corner down to Leaming Bar Services, that has a speed restriction on it.
Hopefully Dave (deebee) will update us soon, when he travels down to at the Broads. Thank you TheQ, TomTom warns me of the dreaded speed cameras.
Iain