I’m not sure.
There are partial C++ savedmodel instructions here: Using the SavedModel format  |  TensorFlow Core
IDK what the status of the new C saved_model api is: https://github.com/tensorflow/tensorflow/blob/master/tensorflow/c/experimental/saved_model/README.md 2, but IIUC that just needs the Install TensorFlow for C 2, but that’s 500MB.
Given your requirements TFLite may be your best bet. It does have GPU support, and is designed for space-limited applications.