Planned on doing the same. After pricing the parts and looking at the labor, I found a cheaper, simpler method to have more propane.
I swapped my 20# tank for a 30# tank. Only the cost of the tank and a fill. Same as having the 20# tank but taller. Considered the 40# tank but that would be top heavy in the existing bracket. For extended travel, I’ll throw the old 20# on my rear carrier.
Empty propane tanks decently priced at tractorsupply.com and had free shipping, mailed to my home. My local Tractor Supply has a propane tank fill station, so you only pay for gas received. Only minor PITA is the 30# tank is taller than my truck tonneau cover, so I braced it in my back seat floor area.
So bottom line, gained 50% more attached propane for well under $100 with no labor.
I think having a few of those 5# tanks would be great for a backup if you run out but those suckers are $$ for what you get.