ENO Hot Spot and REI Wide 3.5 pad Mod suggestions

Noob mod question.

I bought an REI 3.5 Sleeping Pad for use with my tent. Then, I got addicted to the idea of hammock camping, so I decided to buy an ENO Hot Spot Pad holder.

Nice stuff, until I go to put the pad in and the Hot Spot is about 2-3 inches too narrow. (My pad is 26" wide)

I figure I can just cut the back apart, and then add a piece of ripstop or plain nylon to make it wide enough. Or would it be better to add something with some stretch, to keep it tight to the pad?

Has anyone modded one of these for a wider pad?

Thanks in advance for the help.