Sadly, the tdm-gcc installer executable doesn't support silent or automated installs.
A pre-installation on Appveyor would be really helpful.
Normally i install with type "MinGW stable, C++" and zip the install folder to make it portable.
I would like to upvote the request to pre-install MinGW 32 and 64 through their chocolatey packages.
I am trying to run an extensive matrix (all architectures, all compilers, statically and dynamically linked) and these packages work fine but take time and create stochastic 404 failures when they are being installed.
Nah - the vanilla versions installed using choco (as mentioned above by Timotei) are working fine for me.
IMHO doing combinations on libraries would be beyond the limit of keeping things reasonable.
BTW. You can't regularly install both 64 and 32 bit versions on a single system, as they are two flavors of the same package for choco. This will requires manual copying both into to same image or making choco force-install the second flavor.