Possible? Yes. Practical, not so much. Even if you have NFL quality receiving, high-gain antennas, antenna amplifiers and top tier receivers, the transmitters sending the signal would need to be top-tier as well to over-come distance and obstruction. My RF plan has always been, use the best gear and get the receivers as close to the transmitters as possible.
Add to that that it will be hard to determine the frequency of the transmitters inside without very specialize equipment and even then, the transmitter inside may use a pilot tone that will render your receiver deaf even if tuned the the proper frequency. Seems like a very tall ask. Sorry.
D.