@John Dallas Welcome to WNC. I would consider the cost of extracting your equity from the FL property by sale and then compare that to pulling equity by way of a cashout refinance. I don't say that to be self-serving, being a lender. There's also the fact that you'll stop growing equity there, when you could instead access most of the equity and keep growing wealth through the home. I saw your comments about not wanting to manage properties in two states, but perhaps you can find a great PM for the FL home.
Regarding the numbers you mentioned above, it very much depends on the specific location. I would highly recommend you create a Market Report in PriceLabs to see how similar properties nearby are actually performing. It's a $10/mo subscription that you can turn off after starting it, meaning you'll have 30 days to play with it. You'll likely find it easy to find people who will tell you what you want to hear, but you really need hard facts not speculation.
But for some speculation, if you're talking about the Nantahala River or Little Tennessee, sure I think you might be able to do $22K/yr, but not much more, unless perhaps the places are uniquely styled. Down around those areas you'll be swimming in a sea of cabin competition, so a Scandinavian style or something otherwise standout might be the only path to making more.
That said, I personally don't think $22K/yr gross x 6 separate dwellings are good numbers for an $800,000 investment, not to mention costs for furnishings and such. Perhaps the numbers will turn out to be much better, but I'd be careful to not let your personal love for the area lure you into an investment that you might someday loathe due to ill performance coupled with management headaches. And I would perhaps instead start with one to make sure it's going to work well.
On another note, living near the Swannanoa River myself, your comments about building cabins on a river give me pause. Quite a few investors just lost a ton of wealth here, so be careful about nearness to a river, elevation, etc. And be sure your insurance costs won't be insane.
Finally, if you're near Asheville at times we have two BP meetups per month here. We'd love to hear more about your ideas, share some others, and help in any way that we can. I can add you to our events list if you DM me your email address.
Hope this helps.