I've been working a little more today. I have those seams fixed and have developed the land around the manor, one cell out. I still haven't decided what sort of land I want this to be...pine forest with green grass, tundra, or fall forest like the Rift. Regardless, it'll be a lot of open space with "spots of interest".
that might depend on where you plan to place the enterance to the Sanctuary IE if your in the Rift and surround by trees you don't want it to suddenly go all l snowy.