The "chrome delete" on the newer cars is anodised aluminium. This wouldn't be possible to do to the existing brightwork at a practical cost.
This leaves two options really:
1) Getting your existing chrome trim wrapped. This would a few hundred at a reputable place, or you can do it yourself with DIY kits. The downside is that its a wrap so can peel if not applied properly (or just after wear and tear), and it will be nigh on impossible to do all of the bits properly - e.g. the inside of door handles.
2) Buying the new dechromed trim once it becomes available. I would imagine the cost for this, from Tesla direct, would run to several hundred pounds, probably getting on for £2000+ if you buy two replacement wing mirror assemblies and 4 new door handles too.