Sorry no help with your stock Chevy mirrors but towing our 25' Winnebago (8' wide) with our F-150 is doable with my stock mirrors but I wouldn't do it all the time. I do have clamp on extension mirrors that I use when we are actually on a trip and I wouldn't want to be backing into sites without them.
The only time I don't bother with the extended mirrors is when collecting the trailer from the storage lot and bringing it home to pack etc. and that's a simple 5 mile drive.
I can see down beside the trailer with the stock mirrors if adjusted properly and I lean my head to which ever side but I wouldn't want to be changing lanes or driving on busy multi lane roads with the stock mirrors. Sorry, probably not what you want to hear, but is the reality of using mirrors that are not as wide as what you're towing behind your truck.
These are the clamp on extended mirrors I use, they show them as available for your truck...
https://www.etrailer.com/tm-2020_Che...erado+1500.htm