Hi Jim,
we may make a similar sized photoreal area with seasons so that it fully matches our ground textures throughout the year.
By the way, the disadvantage of wide blending strips is that you'll end up with a fairly significant autogen exclusion within that blending strip. For that reason I try to keep blending of photoreal backgrounds to a minimum and instead follow existing edges within the photo area, like roads, fields, suburban borders, etc.
Cheers, Holger