New French doors and existing carpet

[Ontheladder]

I'm having new French doors installed, the window and wall are being removed. I've just realized there will be a gap where the carpet won't meet the new doors due to the existing window being a box window. What can I use to bridge the gap between the existing carpet and the new door? I don't really want to have to buy new carpet. The gap will be 4-6 inches along the width of the French doors. Thanks

 

[pilsbury]

A thin flat piece of hardwood perhaps stained or varnished and fixed down. Like a wide door threshold.