With remote work, it's about what you can show for it, not just the words. What do you have to show for what you've learned?
In this period, I learned a lot about remote collaboration and the importance of communication. A lot of people go on about tools like Slack etc. but in my experience, the phone is still the most important tool. And good desktop-sharing software like Webex, of course.
Eventually I got tired of contracting and took a remote job with a Very Large Silicon Valley Company. Crucially, to get this job, I needed to point to both my depth of experience and my time as an effective remote worker.
So in my opinion, to start with it's important to work a normal go-to-the-office job for a number of years and successfully ship software.
That said, your advice is good in general: a portfolio is essential for junior developers who want to distinguish themselves enough to qualify for a remote position.
I'm revamping all my projects and my site based on some new things I've learned. I'll be sure to post some here for feedback this month. I don't want to embarrass myself in this community (done that before under my old username, not fun).
Thanks though for the real question I should be asking myself and the mindset I should have.