I think this will be the year that we'll start seeing Xs dip below $50k but those will be lower end, bare bones models and not in the greatest condition (I've seen cars with bubbling paint, dents and heavy scratches come up for sale). However, keep in mind the $2k delivery fee if you don't pick up the vehicle and with higher mileage, you'll be limited to the 2 year, up to 100k mile warranty.
There's another site that aggregates used Tesla data:
TeslaCPO.io - Search Tesla's Vehicle Inventory
It's not nearly as nice as EV-CPO Hunter but it will show you historical data so you can get an idea of how pricing changes. What I noticed was that they drop the price daily by a small amount until the car sells. You'll see cars pop back up too if someone bailed on their reservation. Just be diligent about looking and something will come up.
I was in the same boat as you for the longest time until my wife's old car gave out. We lucked out with a great condition Silver 2016 75D with only 33k miles all the options we wanted for $56k and a 4 year, 50k mile warranty. And it was located a few hours away so I picked it up with no hassle.
One question though: if you're okay with higher mileage, why not also look at private party or auction?