I Have just update the function Get-DC to version 1.1 . The function is now AD site aware and will still use your computers AD site if it is not specified.
You can find the version changes below or on the download page.
Function name : Get-Dc
Authors : Martijn (scriptkiddie) van Geffen
Version : 1.1
10-10-2016 V0.1: Initial Script
06-12-2016 V0.2: updated script with credential support and doubble ping
12-12-2016 V1.0: Fixed a issue with the credentials when querying from a domain joined PC
01-17-2017 v1.1: Updated “Site” param to “ADsite” and try to resolve default AD site if the param is not specified