For Reolink Go, data usage depends on the bitrate you have set for the camera. The default bit-rate is 1.5 Mbps for the mainstream (up to 2 Mbps) and 160 kbps for the sub-stream (up to 512 kbps).
With 1 GB of data plan, under the default settings, it can be used for continuous live video viewing for 1 hour in the mainstream type(clear mode). And about 10 hours in substream type(fluent mode). Under normal usage 1 GB data monthly will be enough.