I bought a charging usb c to hdmi converter on ebay. I worked great at first. Charging at 1 amp from tv usb allowed phone to be mirrored without rapidly dropping battery. For the first 30 minutes battery % never dropped nor went up but it did show as charging phone. A connection with no charging capabilities would drop at least 5 percent in a half hour. After about an hour I started having problems. Unit would just disconnect for no apparent reason or on one occasion it froze the phone screen black. I had to pull battery to restart. I don't know if the unit is at fault or Netflix because I was getting a Netflix error 0013 box popping up once in a while. Really a disappointment because it was perfect for the first 30 minutes. I must say, however, picture quality looked a little better on Miracast which is very strange. I was getting 1080p (I don't have a 4k tv) but picture looked a little darker than normal using the adapter.
I would try the Analogix slimport adapter but it is still expensive and without charging capability phone battery drops very rapidly while streaming Netflix according to all reviews.
Miracast while connected to charger may be the best solution. I just prefer a wired alternative.