High Sierra Topix

I know you can get them at Whitney Portal and Tuolumne, but do VVR or MTR stock these?

Muir Trail Ranch does for sure. Here is what they say on their website

"Before you call us, we DO have propane canisters IN STOCK AT ALL TIMES. You do not need to reserve one. We also keep ample white gas and alcohol.
(We get literally hundreds of phone calls about propane canisters.)"

Most likely VVR does to as people send their resupplies there.

But just pick one up at MTR as you pass by and you won't need another one until Reds.

VVR also carries canister fuel. In addition they sell alcohol and white gas by the ounce for people using those stoves. In general the store at VVR is quite well stocked. I'd say that once you resupply at VVR or MTR you shouldn't need to leave the trail at Reds, just keep on plodding along. If you are heading South this is a mute point as there is no more close resupply. Have a good hike.
Eric