@DesertNomand, sounds like you need T182 or Piper Turbo Arrows to train at that high of a DA.
Would you believe there is an outfit in Truckee that gives primary instruction in a 172M? That's 145 screamin' horses.
It can be done. It's not THAT high. Heck, I've been into Big Bear in a 160 HP Warrior, with 8000+ DA at field elevation. And climbed with it at nearly 500 FPM up over the ridge to 10,000 feet. Warriors aren't that great at altitudes like that (it's an issue with the airframe -- an Archer isn't any better even with 20 extra horses), but it can be done.
The DA is much less of an issue than descending air. That's where you can get into trouble.
Sounds like you may need to review your aircraft's performance numbers. The local CFIs really understate performance. Severely. 8000-10000 DA isn't a big issue unless you insist on the same performance you get at sea level (which will give you a departure stall), and you know how to lean. You do have to be aware of what the winds are doing, more so than at sea level. But not train? That's just not correct.
For the record, a 172N can get to 50 feet from South Lake Tahoe in 90 deg heat with two adults, a 50 lb kid and full fuel, using well under 4000 feet of runway. BTDT, with more than half the runway (still > 4500 feet) left over to land on just in case I had trouble.
Summer training is done early for several reasons. The DA is better in the morning, but you're nowhere near the service ceiling unless you're headed south AND over the Sierra. More important reasons are winds and turbulence, and especially, heat exhaustion. Training at Edwards is done real early for this reason. Altitude is less than 3000 feet; DA is not severe (though it has to be accommodated). But physiological reasons are dominant.
Back to the point at hand, I think just about everyone gets the student pilot equivalent of senioritis at the end. That close to a goal, you want it to get done. But that desire can very easily get in the way of the goal. To deal with that, you need a bit of a Zen approach. Do your best in every way, and the checkride will just happen when it's time. I know; easier said than done.