In this paper, we focus on the development and realistic field trial evaluation of a Tele-operated Support (TeSo) service for remote driving over 5G mobile communications. The presented prototype was created within the context of the transport vertical of the "5G HEalth, AquacultuRe and Transport (5G-HEART)" 5G PPP Phase 3 project and was meticulously tested and evaluated in several realistic test cases over a commercial 5G Non-Standalone (NSA) deployment. A vehicle equipped with appropriate sensors and actuators was actively controlled from a distance of 36 km, exchanging sensor data and video streams in the uplink and vehicle-control commands in the downlink with the remote operations center. This work is among the first experimentally-driven quantitative analyses of such an application with a real pilot using an actual vehicle. Our objective was to validate the feasibility of the proposed TeSo service by evaluating relevant performance metrics, such as latency, jitter, throughput, and loss rate. Moreover, our extensive testing aimed to identify salient features and emerging challenges from the prototype, which can aid in a two-fold manner: first, paving the way for the eventual commercialization of the service, and second, guiding standardization effort for a relevant emerging market in the near future.