When I want to change from double quotes to single quotes, I\'m used to selecting the double quote, and then type a single quote. I\'m intending to use the overwrite feature
It is possible!
"editor.autoClosingBrackets" : "never"
(Located in settings.json which you can open in Editor via File>Preferences>UserSettings)
Sadly this setting covers ALL auto wrappings. Including braces, double quotes, single quotes and brackets. You cannot control them individually
UPDATE: autoClosingBrackets is obsolete. The new suggestion is:
"editor.autoSurround": "never"