Just received an announcement Ridg-U-Rak is changing their standard base plate to 5" wide by 6" deep to address future permitting requirements. Where there is smoke there is fire, expect many more manufacturers to follow suit.
We offer our item 70002 wide base plate steel upright protector as a conventional approach.
Our 70025 Compact Seismic would also work noting the front base is 8" wide, so it would extend 1.5" on both sides, some might not like the look, but it'll work.
The 70190 and 70240 plastic rack guards attach to the upright irrespective of the baseplate size.