There are ways to disable Windows 10 updates by adjusting services and using Group Policy. If you have the Professional version of Windows 10, this may be a viable option, though it's important to run a full update once in awhile, when you have the bandwidth. This is explained in great detail in this article, namely:
Via Control Panel > Administrative Tools, you can access Services. In the Services window, scroll down to Windows Update and turn off the process. To turn it off, right-click on the process, click on Properties and select Disabled. That will take care of Windows Updates not being installed on your machine.
And
Setting your network connection to ‘Metered’, can also stop Windows 10 from automatically downloading the Updates. You can do it as follows – Settings app > Network & Internet > WiFi > Advanced options. Move slider to On position for Set as metered connection. See how to set Metered Connection in Windows 10.
For Windows 10 Pro/Enterprise with access to Group Policy:
If your version of Windows 10 has Group Policy, you can also change some settings using the Group Policy Editor. Run gpedit and navigate to the following policy setting:
Computer Configuration > Administrative Templates > Windows Components > Windows Update.
On the right-side, double-click on Configure Automatic Updates and change its settings to suit your requirements.
I hope this is able to help. It may be easier than the alternative of port/connection filtering. If you want to run updates on your own time, without re-enabling the update service, you should be able to find some handy powershell or batch scripts for this purpose in the MSDN community.
