Good question (and definitely send me a link to the map when you’re done)!
Re the Glovers and Tallharts: I would lean to separate, since they still have the right to tax and levy military support from those lands, and GRRM has talked about landed knights potentially being quite powerful. Maybe color them as alternating stripes between Stark grey and their own house color?
Re Stony Shore and Sea Dragon Point: WOIAF says that the Stony Shore was ruled by House Fisher, who became vassals of the Kings of Winter. We don’t know whether they survived the Ironborn incursions, but I would guess the lands are held by some vassal. Sea Dragon Point was once ruled by the Warg Kings before the Starks conquered them, but we don’t know who rules it now and whether they survived the Ironborn either.
Re the Mountain Clans: definitely separate. They are vassals of the Starks, but among the more independent given their distance and traditions.