What is your average daily mileage? I hiked most of the JMT last year (Tuolumne Meadows to Onion Valley in 10 days) with a BV450, resupplying at Red's & MTR. 3 days to Red's and 3 more days to MTR, and the 450 worked great, but it was crammed. From MTR to Onion Valley (4 days), I also needed a large Opsak for more food. And Whitney Portal is about another 34 miles more than Onion Valley. If you prefer to fit everything into a canister along the entire trail, you will need something bigger, unless you're planning on huge mileage days, or resupplying again after MTR, or plan on using alternate food storage (Opsaks, bear-bagging, etc).
FWIW, the Opsaks worked great for me last summer - no bears or varments got wise. But, I'm doing the entire trail this August, resupplying only at Red's and MTR again, and will bring the BV500 this time.