If you can get to Whidbey Island perhaps you can get your hands on some locally roasted coffee from Foxglove Farms. Their 2 lb bags are around $25 so while I'm not aware if they do 5 lb bags or not, your other criteria are met. Maybe they ship, idk, but here's their info and you could contact them to check. It's really good coffee. https://whidbeyislandgrown.localfoodmarketplace.com/Producer/662bfd99-8665-4d9c-ae9a-2d634cb6d502

Most if not all counties have some form/amount of subsidized housing. Not enough, generally, but some - In my county the wait time to get into one of these apartments is over 5 years. Google the county you want housing in along with "area agency on aging". You should come up with an office you can call to get a list of the subsidized housing options in that county. Although it's titled aging, most of them also serve people with disabilities as well. I worked at one, and got lots of calls from people on SSI who were having to become homeless and/or move away. It was (and still is) really sad.

Moisture content is specified in the law and it has to be really dry, overly dried imo.

Look further into the transportation situation before choosing Whidbey. Buses are free but limited in where they go and how often/how late, and they don't run on weekends. Island Transit is the name to Google for that. There is no Uber/Lyft on Whidbey. Taxis are extremely limited as well, south of Oak Harbor it's I think just one company with only a couple cars/drivers so it can be a long wait and costly (though not always... Plan ahead, call them and make reservations). Depending on where you want to go and when, it could be awesome, but without a car I'd definitely check those details first. I don't know at all how this compares to Bainbridge.

Also Whidbey has tons of forested areas especially on the south end. South Whidbey State Park, Trillium forest, and Saratoga Woods are all forested and awesome trails to check out. Greenbank Farm also has a portion of trails that go through the forest (and great views from the non-forested off-leash dog area. And of course like another commenter said, Fort Ebey, Fort Casey, and Deception Pass are all worth visiting.

Edit: Island Transit does have some routes on Saturdays, none on Sundays.