I have managed to get everything working, I believe.
On Windows 7.
Trellis, Bedrock, Sage. Everything works. All of the Trellis deploys work, Bedrock works, Sage works.
I ran gulp --production on local to create the theme assets. Then I ran the two ansible deploy commands (the server.yml one and deploy.sh), and then I copied the database over after doing a find/replace on it.
But it works. Now my site from my local vagrant dev environment is up on my staging server (subdomain on a digital ocean droplet).
So if anyone is using Windows and trying to get all this shit to work, feel free to shoot me a question. Honestly this has been such an ordeal that I think it would take me a week or so to get it all down in writing, but at this point I feel qualified to help someone in a similar situation.
Sorry if this is off topic, I just can’t believe I finally managed to get EVERYTHING working end-to-end, and although I was able to find what I needed across the various topics in this forum (great info all over this place), I definitely had to do some searching. So hopefully I’ll be able to “put it all in one place” for anyone running into the issues I’ve had to deal with getting this all figured out.