Hi, Mike. Been reading your blog for awhile.
Another Dr Pepper ICEE location is the Buc-ee's on Crabb River road just south of Hwy 59 near Greatwood. They have had since they opened about year and a half ago.
I looked it up, it's Buc-ee's store #31:
1243 Crabb River Road
(1/2 mile south of Hwy 59)
Richmond, TX 77469
Icee full coverage