Depending on the number of locations, would using mobile laptops with a customized, streamlined satellite be an option?
My previous customer had 155 customized, streamlined satellites across Norway, Sweden and the Baltic countries. They ran the RCA OS Manager service on the central Core only, while the RCA OS Manager service on each satellite was inactive (both on the full-service and the customized, streamlined satellites). The RCA Boot Server PXE and TFTP services were only active on the customized, streamlined satellites, allowing the Windows 7 and Windows 10 clients to pick up all resources required for the OS build process locally. This setup is not standard, and thus required a little bit of tweaking, but it worked beautifully.
Would having a number of such satellites on laptops and sending them around from site to site work for you?