The MI TV show is way more grounded than the movies, and I'm not talking about the multi-million dollar action pieces, but rather on a more fundamental level: the MI team is supposed to be in and out without leaving a trace, using confidence tricks, illusion, misdirection, infiltration, etc. They even had roles like the roper, the con man, the actor, the muscle, etc. Much of the tension comes from them nearly being discovered. In the real world, that's exactly what you'd want a spy agency to do.
The MI movies are fun (imo only 1 and 2 are the weaker films in the series), but much of the action are pieces that would easily make a breaking news report on 24 hr news -- the opposite of what a military would want to do, never mind a spy agency. The movies occasionally do the missions the old TV show style (classic example being the CIA infiltration sequence in the first movie), but for the most part, they still delve into movie fireworks a lot.
The four Soderbergh Ocean's films -- while comedies -- are much closer to the old Mission Impossible style, and are pretty successful in their own right. It'd be really easy to turn that into a spy thriller, and Tom Cruise can still get his laps in.