I worried about needing mirror extensions for my Tacoma / FWC camper setup. I looked at all types of mirrors and decided on no extensions until I tried driving without them.
The reviews for the clip or clamp on mirrors to true existing mirrors vibrate making them difficult to use on highways.
I have been driving enough now to say that mirror extensions are not needed for my setup. The camper is not that wide, although you can sleep side to side.
I highly recommend the convexed blind spot stick-on mirrors (in picture above) for everyday driving, including the camper travels.