There is a great Codeplx project that allows you to update Portal Settings for multiple team projects at the same time: https://features4tfs.codeplex.com/. Whenever you upgrade TFS, and have to re-enable and re-point team projects in your upgraded TFS project collections. If you have a lot of team projects to update, it becomes very tedious task. Feature4TFS tool allows you to update all of those items in one step. Very handy tool. The only issue with this tool is that it does not work with TFS 2015 Update 3 (only Update 2 or earlier.
I have downloaded the source code and updated the solution to make it work with TSF 2015 Update 3. You can download updated solution from https://1drv.ms/f/s!AoNW-kvNWJ9ygsNWPA5LHTJ5fYREXQ. There two files: binaries only and source code and binaries.