Pretty sure you can use the current template and simply upgrade it yourself with "pacman -Syu". This is the beauty of a rolling distribution. Unless the template is really old (and they changed the way pacman interacts with the repos), you should not have any problem. If you want to upgrade the kernel, you have to use the new control panel do select a newer version. Not sure if they added the latest yet.
I still think D.O. should hurry up and let us use our own .ISO images to install whatever we want (including *BSD). I understand that it means less control on what is running on their nodes and could potentially lead into security issues, but it would be much more simple for the customers to be able to upgrade their servers whenever they want, or use custom kernels.