I believe Cycles (the Blender renderer) only relies on CUDA [1], so it should work. Depending on which AMD card you had on your Mac, it sounds like it might not be supported by Cycles. Because the NVIDIA K80 doesn't do Display though, you'd need to run say vnc or run Cycles from the command line.
My iMac 2011 doesn't work with GPU Cycles but that's OK. And I've successfuly boosted render times by renting the multicore VPS by the hour already (commandline, specify different frame range on each machine to render).
[1] https://docs.blender.org/manual/en/dev/render/cycles/gpu_ren...