[Update 17-Jan-2015] This issue seems to be resolved in the January 2015 firmware update (at least for me): firmware update details.

A post about a non-SharePoint subject: issues with limited connectivity using WIFI on the Surface Pro 3 after putting the Surface in sleep/hibernate state. A lot of posts are already done and Microsoft already released multiple fixes, but for a lot of Surface users it doesn’t fix the issue.

This post describes a workaround to automatically reset (stop/start) the WIFI connection when the Surface is started from sleep/hibernate:

1. First you need to enable script execution via Powershell: Open Powershell and execute the command: Set-ExecutionPolicy Unrestricted
2. Create a new Powershell script on C:\ (e.g. restartwifi.ps1)
3. Add the following command: restart-netadapter -InterfaceDescription ‘<your wifi card name>‘ -Confirm:$false
   You can find your WIFI card name via Device Manager -> Network adapters.
4. Create a new Scheduled task via Task Scheduler
5. Give the task a name, for example: “Restart WIFI after sleep or hibernate”
6. Set it up to run as the “SYSTEM” account
7. Under the “Triggers” tab, add a new Trigger
8. Begin the task: On an event
   Log: System
   Source: Power-Troubleshooter
   EventID 1
9. Go to the “Actions” tab, add a new Action
10. Action: Start a program
    Program/script: powershell.exe
    Add arguments (optional): -File “C:\restartwifi.ps1”
11. Under the “Conditions” tab, uncheck the “Start the task only if the computer is on AC power” checkbox, otherwise this workaround will only work when your Surface is charging
12. Click OK and save the scheduled task
13. If you run the scheduled task you can see that your WIFI adapter is restarted next to your system clock
14. Now put your Surface to sleep/hibernate and start it up again. The limited network connection issue is now fixed