You just need the index.html file and the main.[bundle_hash].js file. You can scrape out the Google Tag Manager import from index.html if you want, though I didn't check to see what tracking it was importing (probably basically analytics).
But so long as you have those two files in a folder, you can open index.html and it'll work fine. My friends and I have been putting in joke words in a shared clone for each other and hosting it on GitHub Pages.