$ sudo apt install gcc-multilib
$ sudo apt install gcc-mingw-w64
$ GOOS=windows GOARCH=386 CGO_ENABLED=1 CC=i686-w64-mingw32-gcc go build -o hoge.exe hoge.go
$ GOOS=windows GOARCH=amd64 CGO_ENABLED=1 CC=x86_64-w64-mingw32-gcc go build -o hoge.exe hoge.go
amd64のほうは未検証