Based on this, you are using Dexcom G4 or G5. They are much easier to restart. The more recent G6 has different versions of transmitters, with increased checking for reuse, so there are multiple sets of G6 instructions based on transmitter version.
The link for See My CGM is mostly about G6.
For G4/G5, you can wait for sensor to end, then simply do start sensor without putting in a new sensor. You have to wait the 2 hour warm up again, but then readings will start again.
Or you can stop sensor, then just do start without changing sensor (G4/G5 only). This lets you pick convenient time for 2 hours without readings.