When the EMM notice appears, you can postpone it for 1 day. If you just want to postpone it until later that day, you can choose the postpone option. Each time you turn the car off and back on again that day, the notice (and postponement option) will reappear. You could, for example, choose No and drive on battery until you’re stopped at that traffic light just before you get to the downhill portion of the drive, then turn the car off and back on again, and start the EMM there.
The EMM process uses only ~0.03 gallons of gas, so there’s really not a lot of optimizing to be gained by plotting how and when to run it. It doesn’t take long, and if you run it while parked you shouldn’t accumulate any Gas Miles or break a streak of days driven on electric only. At least, that’s how it is with the Gen 1 Volt... the EMM starts as soon as you push the Yes choice on the display. The Gen 2 EMM doesn’t start until after a short delay once the car is shifted into D. I suspect you could choose Yes, then shift into D with the foot on the brake, then shift back into N once the ICE starts running.
The EMM process uses only ~0.03 gallons of gas, so there’s really not a lot of optimizing to be gained by plotting how and when to run it. It doesn’t take long, and if you run it while parked you shouldn’t accumulate any Gas Miles or break a streak of days driven on electric only. At least, that’s how it is with the Gen 1 Volt... the EMM starts as soon as you push the Yes choice on the display. The Gen 2 EMM doesn’t start until after a short delay once the car is shifted into D. I suspect you could choose Yes, then shift into D with the foot on the brake, then shift back into N once the ICE starts running.