I would argue that once it begins to fail to start reliably, that’s when it could leave you stranded! The compression readings when it begins to behave like this will vary from engine to engine… and climate to climate.
Bottom line, when it begins to be hard to start and the battery and spark plugs have been eliminated as the cause, you need to start shopping. Until that happens, or until you become unhappy with its performance, keep on truckin’!