Rico Loma

Well done Matt!  So glad to hear that news.  Maine is a gorgeous state with endless forests, rugged islands, and a distinct culture.  
In addition to all the excellent suggestions,  I might add one other potential income stream.  
I know a few folks, mostly  Southerners, who have fallen in love with Maine, especially spending summer vacation time there away from sultry GA.
Could you dedicate a small portion of the land for a campground, maybe just 5 or 6 tents with a communal shower/ outhouse?  That could  bring nature lovers at least half of the year, and not be an overwhelming commitment.  

So happy that you are opening a new chapter, smiles all around, I predict a monster success for your efforts.

Perhaps a sprinkler system with motion sensor? Cats don't like to be sprayed.....

This seems a bit outlandish, but hear me out.
Polysomething roofing does have a lifespan,  and you have a fierce sun in the tropical regions.....is it getting brittle due to age? Near its useful time on earth?
My idea would involve removing the current roof. Either repurpose the material or feed a hungry landfill.....no, that's not a green solution, but we all require a modicum of sanity in our lives.  
Your new roofing will be a steeply pitched affair, rendering it impossible for cats to defecate.  

Addendum:
This is on the record, and  what initially made  me leary of sporty diesel cars , not just complicated VW engines but in general.  Look at the percentages!    If global trends continue for fossil fuels, the farmers (  perhaps needing fertilizer AND diesel 2or 3 times per year   ) and all of us should  pause , consider how to adapt.

Over the past year in the US, the average price for diesel has risen by about 63% (from roughly $3.70 to over $6.05 per gallon) .....wow.  
That is 2 days back, when seeing  this on AAA.
Regular gas up by about 35% (from roughly $3.19 to $4.29 per gallon).

Hey y'all, is there a permie revolution afoot?,,,, Go green now

This may sound like a broken record, sorry,  but he is still a smash hit, platinum status....please consult our friend Mr Chickadee.
Their work is common sense yet phenomenal,  see the stellar timber framing , Japanese style.  

The scale of course is  smaller, but he demonstrates an ancient and proven technique.  But i could propose,' well Gulliver can you learn a skill or two from the Lilliputians? '
Here's one shot of the foundation details with selectively charred wood.

......of all mankind.......

Glenn  and  Christo certainly describe some things to consider. Again, describing your location, soil composition,  etc will help these two masters of the craft advise you.
Is this your first project using 30' tall posts? We're they about 3 tons each?  And the boulders might weigh the same to support the posts, to prevent movement after placement.  Keep it safe, we can't lose any Permie folks, for the good of all ma ,ind.  

Thomas thanks for the Montana terrain, it sure varies in my travels across the lower 48.  I was just using national averages for the comparison.  
At our local stations , we see 6.15 for diesel per gallon. whereas i  Just filled up my Honda Fit with gasoline today at 3.92 per gallon.  
The Fit averages 44 mpg with mixed city/ highway, that is over the latest 1000 miles. Much different machine than your gas car, different strokes for far flung folks.  

it's so interesting to see the US map and register the differences....we are 7 hour drive from Gulf coast refineries, perhaps that makes a big impact on price?       (Certainly state taxes affect the price too, in March or April our Governor Brian Kemp stopped taxes on fuel for months, in response to exploding fuel prices.  That lasted two months, if memory serves.    Now we have full taxation again.  )  In the long term, I hope that us blue collar workers see some help on prices , only God knows when that will come to pass.  

I hate to bring this up....caveat emptor
Diesel in the EU is now 8.90$ per gallon if gallons were sold.   🇺🇸 prices are over 6$ , and that's up 60% since a year ago.
Does anyone think prices are coming down soon?  Reading yesterday's news did not fill me with much confidence.  That 55 mpg is not such a bargain when compared to gasoline at the mo

My apologies,  I used block building as a general form of masonry.  Hyper adobe uses soil with rocks gathered on site, that's the style you might entertain for your project