This is a great post and should be somewhere else besides just the gaming business thread.
I love my current career, but also suffer from the uncertainty of knowing I have a much better than average setup (even within this career path) and the sector is going through quite a bit of upheaval that may eventually get to me. I have some relevant skills/inclinations to a development career track and do occasionally envy the geographic flexibility (which my current career certainly is not, outside of pandemic).
I’ve often thought, and still do think, that if I suddenly lost my job (or, absolutely needed a change of place), the first thing I’d do is enroll in a intensive boot camp along the lines of what you describe. Your post makes that sound like a decent plan.