I've updated 7 PCs and 3 VMs of my own, plus 5 for a business client (there are still 3 to go, 2 of which say they aren't ready yet). All went OK on 6 of the 7, the seventh (HP Zbook 17G2) warned me at the first that there wasn't room in the very small hidden partition used for booting. Did a search, found out how to make it visible and see what was there. I had recently updated the BIOS on the machine, and it had both the new and old BIOS in different directories. Copied the old one just in case, deleted it from the partition. All was well.
It did, however, take considerable time, especially on the slower machines.
In general, I've had better results using the Windows Update Assistant, it makes a few extra checks at first.
Tried an experiment with one of mine that "wasn't ready" Made an Acronis image backup just in case, and forced the update anyhow. It ran all night (slow machine), and didn't boot OK. Booted it into repair mode, it proceeded to remove the update and come up OK. Since then, the same computer has said it was ready, and the update went with no problems.