Boy do I have a follow-up! My specific issue had nothing to do with the charcoal filter, even though the local Toyota dealership said that's what the issue was. The dealership wanted to charge me $1,700 to change out the whole charcoal filter assembly.
I found an auto shop closer to me that will work on Toyotas. Had them look at it. They inspected the charcoal assembly and said there were no air obstructions in that. What they ended up finding; a hose by the gas tank was somehow clogged. At first they assumed critters or something. They ended up having to remove the tank in order to replace the problematic hose. It's about a foot long & ~1.5". On the invoice the part is called a "fuel filler neck (lower)". Anyway, out the door they ended up charging me just over $1,000. I was thrilled with that.
Had I allowed the dealership to work on this, I would have paid WAY more, and it wouldn't have fixed the problem. The auto shop guy said they likely didn't properly troubleshoot to figure out what was wrong. Just Googled it and diagnosed based on the common issue.
So I just picked my car up, and the mechanic handed me the hose. Laughing; he said he's never seen anything like that before. Took some pics:
https://imgur.com/a/DHI8NiU
If you happen to live in the Grand Rapids, MI area... don't trust the Toyota dealership.