GTK+ 2.0/3.0 Windows runtimes

[John Mills <johnmi effect net au>]

Hello list

If this question should be raised on another list, please let me know.

I have been developing a C-language GTK+ 2.0 application for MS Windows 10 using mingw 
cross-compilation on Linux, and deploying it by installing the Windows GTK+ 2.0 runtime 
bundle on the Windows machine.
http://ftp.gnome.org/pub/gnome/binaries/win32/ 

The procedure was: on Linux development machine, unzip the gtk Windows bundle in a directory 
with the C source, set up a Makefile with the appropriate CFLAGS and LDFLAGS, 'make mingw' 
and deploy the EXE. This procedure suited my development style.

Do I now need to port to GTK+ 3?
Is MSYS2 now the best/only way to deploy the dependencies to Windows?
Using the binaries available through MSYS2/pacman, can I still develop on Linux and deploy 
mingw executables to Windows?
Can anyone point me to a guide for doing that?

Thank you
John Mills