Suggestions for stops / visits - Holkham park, hall & beach; Walsingham - & spend a bit of time exploring the religious history via the Norton tea rooms, Wells-next-Sea for a view up the channel to the lifeboat house, Castle Acre cafes castle river & priory, Binhan Priory, Sandringham, Blakeney, Houghton Hall - may not be open. Most of the country roads are very quiet, but it is the sugar-beet season so could be muddy in places with FLINTS !. The coast road tends to be busier, so dip in & out.
I hope the weather is kind to you.
bazzz