If you must dual boot, have totally separate hard drives, and the choosing between Linux and Windows should be done in the UEFI boot menu, not GRUB menu. Windows can render Linux unbootable otherwise, requiring a rather complicated rescue. Windows would ideally not have any chance to see the Linux hard drive while booted.
An external SATA SSD in a USB enclosure is cheap these days.
An overburdened-with-users server could discontinue allowing new sign-ups on their sign-up page, but rather post a link to a list of where willing-to-accept-new-users servers are.