I seen no reason to change oil any earlier using 5W20 or 0W20 then using 5W30. As noted in many previous posts, I have used 0W20 Mobil 1 exclusively for the last 275k miles on:
My 94 Escort commuter Car.
3.1 Litre Lumina APV tow vehicle.
As a diehard snow skier, in the mountains a lot every winter - & using the 0W20 Mobil 1 - you will often be the only car starting in the parking lots each morning, if temps go to -30f or below.
I have done only 20K mile changes on both these cars, and both seem to run like new, quiet, no oil consumption, etc.
The tow vehicle pulls 5,000 lbs 4 days a week, and often pulls 700 miles on blistering hot weekends, truly a grueling schedule for a 3.1 litre Chevy V6. This should mean there is lots of reserve in 0W20 for less demanding users.