Especially in the case of having only a single drive: instead of dual booting, I would advise setting up a windows VM through qemu. It might be a bit time-consuming at first, but you don't have to reboot and there's no need to bother with partitioning your drive correctly. The performance is almost on par with dual booting if you set it up with GPU passthrough and CPU pinning, which is mostly just a matter of finding a decent guide and following it. The only disadvantage is that some games that use invasive kernel-level anticheats may detect that they are running inside a VM and refuse to work.