Getting Linux to work on HP Envy x360

TL;DR: If you are here just for the fix (Which I would if I was you), the actual
fixes are at the bottom of the post. Just search “TL;DR”.

After 8 years, my Haswell-era laptop was showing sign of age. While the CPU was never
really a blocking point, despite being a low-power variant, the RAM had been the maximum
of 12 GB for a couple of years and, modern apps being what they are, it was no longer
possible to run Firefox alongside and a virtual machine. A choice had to be made
between the experimentation environment and the documentation. Not ideal.