TSCH is emerging as a reliable access mechanism for wireless sensor networks that, thanks to time slotting, suits the needs of battery-powered devices deployed in industrial scenarios. To take into account the traffic needs of the different links in a mesh network and the related variability, in such a way to prevent instability and butter overruns, overprovisioning can be exploited. It consists in allocating more cells than strictly needed for communication between a node and its neighbors. Unfortunately, overprovisioning in TSCH leads to higher power consumption, because of idle listening. In this paper, two approaches for saving energy are proposed, which temporarily disable listening when no packets are available at the transmitter. Such mechanisms show good backward compatibility with existing TSCH devices, and may coexist with them.