How can I change the default website connection timeout in Chrome?

You can't. Google has been ignoring requests to implement this feature for over six years, so I wouldn't hold your breath.

It's hopeless. They just won't do anything about enabling users to change Chrome's timeout settings. But you could switch to any of four other Gecko-based browsers in common use that have no timeout problems. Or you could start using one of the Mozilla-based browsers.

I dealt with this issue by editing the registry. I think the registry affects not only IE but also Chrome in Windows 10. I tried extend time-out. then I can extend it and max time-out is about 7Hrs in my case.

Reference: Microsoft Support

Click Start or press Win-R to get Run box, type regedit, and then click OK.

Locate and then click the following key in the registry:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\InternetSettings

On the Edit menu, point to New, and then click DWORD Value.

Type KeepAliveTimeout, and then press Enter.

On the Edit menu, click Modify.

Type the appropriate time-out value (in milliseconds), and then click OK. For example, to set the time-out value to two minutes, type 120000.

Make another DWORD value ServerInfoTimeout and set it to the same value.

Restart machine.