within the realms of possibility
From Longman Dictionary of Contemporary Englishwithin the realms of possibilitywithin the realms of possibility (also not beyond the realm(s) of possibility)POSSIBLE used, often humorously, to say that something is possible even though you think it is not very likely I suppose it’s not beyond the realms of possibility. → realmExamples from the Corpuswithin the realms of possibility• It was actually within the realms of possibility.