"W64" are 64 bit wav files and are not constrained by the 32 bit limitations. W32 supports 4GB files, but some programs get it wrong and can only support 2GB.
Not many editors support W64. Sound forge supposedly does.
You could treat the file as binary data. Split it into 2GB or less pieces, and add a header or import as raw.
On linux, I would split the file using the split command:
split -b 2000000000 file.wav