I've successfully installed Ubuntu 20.04 onto a 64GB USB stick, as I only intend to use it occasionally, while having Windows 10 installed on my laptop's SSD.
I installed the Ubuntu with a desktop after unplugging the internal disks, to not mess with the desktop's original OS.
Now that I have a full installation on the USB stick, a question comes to me: If in the future GRUB gets an update, and I update it, will the process mess up my laptop's own Windows boot? Because I can't remove the internal SSD with Windows installed in my laptop so easily, if at the time of GRUB's update, the internal SSD is present, will the update overwrite my Windows Boot Manager and causes issue booting into Windows without the USB stick?