I know that you are hoping for the lending rate to go up so that you can lend out your shares, but it will not go up. If shares available to short are drying up today that is because TSLA is going up and short sellers are getting margin calls, longs are calling back their shares to take profits, etc.
The lending rate will not go up unless there is really bad negative news that could threaten the company into bankruptcy or other failure. The only way that you are going to get the lending rate to go up is if all of a sudden everybody and their mother wants to short TSLA because it is a slam dunk case. This will not happen again unless the stock starts tanking extremely hard (for some good reason).
As a long TSLA holder, I don't think you want that to happen. If TSLA continues a slow and steady climb then you will not see lending rates to go up above the current 1% or whatever it is. You are not going to see double digit lending rates anytime soon. Like I said it is a double edged sword, you will not get good lending rates with a rising share price. Unless of course there is a VW-like short-squeeze, in which case you would be 10x better off selling the shares at a profit than lending them out for a high interest rate that will only last a day or two.
That 85% lending rate in the beginning of the year was an anomaly and it will not happen again without good reason.
If you want to lend your shares, then you are going to have to live with a few hundred basis points at best. Not worth it IMO: all you are doing is increasing TSLA supply and putting downward pressure on the stock.