I have a Sony Vaio laptop running dual boot Windows 10 and Ubuntu Linux.
When Intel releases the microcode for my CPU it will be installed on my CPU during normal Ubuntu software updates, without any need for a bios update.
It's pretty easy to create a bootable Ubuntu USB stick from Microsoft Windows .
If you boot into Ubuntu from the USB stick after the microcode becomes available and run the software updater, the microcode should be installed on the CPU.
https://www.youtube.com/watch?v=fLYBXOVn6ow