1. Bitcoin price approaches 1M USD.
2. Value of USD quickly goes to zero. Everything is accounted in BTC.
It doesn't solve the problem. If for some reason big miners spend on electricity + hardware much more than they get from mining, they will quit business. And it doesn't matter if they pay it in BTC, USD or any other currency. In that case Bitcoin network will be paralyzed and possibly compromised, i. e. dead. Why is it impossible?