In this paper, we assess the suitability of NB-IoT (Narrowband Internet of Things) cellular technology for smart grid applications, concentrating on the reliable and timely delivery of Outage Restoration & Management (ORM) messages at the event of a local or regional power outage. Using system-level simulations modelling of both the cellular NB-IoT and the energy distribution networks for different environments, we present an extensive sensitivity analysis of the ORM service performance w.r.t. various radio network configurations. In particular, we propose and analyze different packet schedulers, an essential mechanism in optimizing the service performance. A key outcome of the study is the conclusion that indeed NB-IoT is a suitable technology for supporting ORM services in smart grids, accompanied with a proposed near-optimal radio network configuration to best do so.