You beat me, I've only been dual booting for about 12 years. It's easier than it used to be if you want to preserve your existing NTFS partition and resize it. Linux tools couldn't do that until some point in the last x years.

When I multibooted Linux, DOS, Windows, and MacOS (Hackintosh) a long time ago, I had a huge FAT32 partition for this purpose as all the OSes could read and write it.

These days, ExFAT should also work for bigger files.