Comment 5 for bug 1854764

OK, just tried the upgrade:

$ apt list --upgradable
Listing... Done
intel-microcode/bionic-updates,bionic-security 3.20191115.1ubuntu0.18.04.1 amd64 [upgradable from: 3.20180312.0~ubuntu18.04.1]
linux-headers-generic/bionic-updates 4.15.0.72.74 amd64 [upgradable from: 4.15.0.70.72]
linux-libc-dev/bionic-updates 4.15.0-72.81 amd64 [upgradable from: 4.15.0-70.79]
mpiadmin@chive:~$ sudo apt install --only-upgrade intel-microcode
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be upgraded:
  intel-microcode
1 upgraded, 0 newly installed, 0 to remove and 2 not upgraded.
Need to get 2.409 kB of archives.
After this operation, 1.464 kB of additional disk space will be used.
Get:1 http://de.archive.ubuntu.com/ubuntu bionic-updates/main amd64 intel-microcode amd64 3.20191115.1ubuntu0.18.04.1 [2.409 kB]
Fetched 2.409 kB in 0s (10,6 MB/s)
(Reading database ... 241276 files and directories currently installed.)
Preparing to unpack .../intel-microcode_3.20191115.1ubuntu0.18.04.1_amd64.deb ...
Unpacking intel-microcode (3.20191115.1ubuntu0.18.04.1) over (3.20180312.0~ubuntu18.04.1) ...
Setting up intel-microcode (3.20191115.1ubuntu0.18.04.1) ...
update-initramfs: deferring update (trigger activated)
intel-microcode: microcode will be updated at next boot
Processing triggers for initramfs-tools (0.130ubuntu3.9) ...
update-initramfs: Generating /boot/initrd.img-4.15.0-70-generic

$ sudo reboot
(wait for reboot, log in again)
$ sudo reboot
(need to do this twice to make sure new kernel is in place)

--> still hang on warm reboot