I don't know the north so well but IMO southern Morocco (tho' not WS for the reasons mentioned) is a brilliant destination on a road bike. Especially in November. Good tarmac, empty roads, virtually no checkpoints, decent hotels and, we hear lately, a lot more unleaded pumps than there used to be. I bet a lot of big bike riders going there looking for off-road action, soon settle for the asphalt but have as good a time.
From Figuig to Tan Tan or Sidi Infi along the 1500-km 'Desert Highway' as I call it, you could have a fantastic week or two with a few side trips via Ziz Gorge, Merzouga, Zagora, up from near Tissint to Taliouine, back down via Igherm to Tata and on westwards. Like the man says, get a map (RG 2009 is good).
As long as it's dry, many tracks in southern Mk are easily doable on a road bike too if you keep the speed down.
Algeria is more out there but especially the south, would be a great road ride too. Much bigger of course but less good infrastructure and all the crap with escorts means you'd want a group to keep costs down.