If you install the Linux bootloader on the other drive with Linux, Windows basically just doesn’t know or care that the it exists to bother writing over it. You can use UEFI to choose what to boot, but GRUB works fine with entries across different drives.
That said, it’s not actually that hard to fix with a live USB if Windows does decide to eat GRUB on the same drive. I’ve been taking my chances on laptops particularly for years. So far, the only real problem I’ve run into was doing something stupid while dead tired and managing to nuke the Windows bootloader all on my own–somewhat ironically, while I was setting up another Linux distro to boot off a new drive! Which was also totally fixable, but a bigger pain than reinstalling GRUB would have been. (Especially with not being nearly as comfortable dealing with Windows stuff.)
If you install the Linux bootloader on the other drive with Linux, Windows basically just doesn’t know or care that the it exists to bother writing over it. You can use UEFI to choose what to boot, but GRUB works fine with entries across different drives.
That said, it’s not actually that hard to fix with a live USB if Windows does decide to eat GRUB on the same drive. I’ve been taking my chances on laptops particularly for years. So far, the only real problem I’ve run into was doing something stupid while dead tired and managing to nuke the Windows bootloader all on my own–somewhat ironically, while I was setting up another Linux distro to boot off a new drive! Which was also totally fixable, but a bigger pain than reinstalling GRUB would have been. (Especially with not being nearly as comfortable dealing with Windows stuff.)