Personally, I would have answered "I will get the Model 3 because that's the car I really want" if that were an option...
I don't particularly like big cars (my wife's outback is the top end of what I consider reasonable). Big cars are harder to park, I don't have a bunch of kids, and I have a pickup for hauling stuff. Plus, size = weight, and weight is the enemy of handling, acceleration, braking, and general fun-to-drive factor. Yes, the MS counters that well, but if you shrunk the MS by 20%, it would be that much more awesome (IMHO).
Currently, I have a pickup for hauling stuff, Home Depot runs, towing boats, etc. My commuter car/fun-to-drive car is a Mini Cooper S. I also have a 911 track/weekend toy.
I'd replace the Mini with an AWD, performance Model 3 in a heartbeat (I was ready to put down a deposit last night on the remote chance it was offered). Instead, I'll probably replace it soon with a used/demo/loaner Model S, drive that for 3 years or so, and trade for a Model 3. If I don't like the 3, maybe I'll swap for a new S85D and keep it for 12 years.
Either way, I'm not buying a new Model S with the expectation of trading for a Model 3 in 3 years, as I don't particularly want to eat the $40k depreciation. I'm the kind of person who keeps cars until they fall apart, vs new every 2-3 years.