For those of you, like me, that live in a front-plate required state but are, like me, going without, I bought one of these.
Admittedly, it's a little pricey. I'm not worried about front plate moving violations - I haven't gotten one on my previous cars - but it's mostly for parking, where meter cops are way more strict about front plates here (at $50/pop for front plate violations, I figure this is worth it). It is made specifically for the refresh S (I'm waiting for my perm plates so no photos yet). Fits perfectly and works really easily (on and off).
I have no affiliation with the company that makes these, I'm just sharing because I was looking for exactly this option:
SnapPlate Model S Removable Front License Plate Mount