Take it to a Tesla approved body shop. There's no reason not to, since the other driver was at fault. I've had my S repainted at John Eagle in Dallas (one of the two Tesla approved body shops) and they did a horrid job. Over spray on the rubber, paint drips running down the side, horrible orange peel, debris in the paint. I wouldn't let them paint my child's wagon. Trade Secret, the other body shop, has painted my S twice and did a great job. They're not fast and their communication can sometimes be spotty, but the finished result was very good.
If there's going to be a huge delay getting parts, convince the at-fault insurance company to pay the extra couple hours labor to have the body shop reinstall the bumper so that you can drive the car while the parts are on order. That way you don't have to drive a crappy ICE car. The other insurance company will likely be unwilling to do that at first because their knee jerk reaction will be that they don't want to pay the extra labor to have the bumper installed and then removed when the parts arrive. Keep pushing on them until you reach a human who has a functioning brain and can comprehend that paying for a couple of extra hours shop time is way cheaper than paying for two months of car rental. I've gone this exact route recently and it was worth the trouble to avoid a nasty rental car for two months.
