Let's say a 2015 US dollar can buy a dozen eggs. At the exchange rate today that's about BTC0.0028. If Bitcoin goes to $1,000,000(2015)/BTC tomorrow like people dream about (and that dozen eggs still costs just $1(2015)) then that dozen eggs will effectively cost BTC0.000001=100 Satoshi.
If the US dollar inflation rate is severe and a 2046 US dollar is worth only 0.1% of a 2015 US dollar then the eggs will cost $1,000(2046). If the Bitcoin exchange is unexpectedly/unlikely still $360(2046)/BTC then it would take BTC2.78 to buy the eggs in 2046. If the exchange rate exactly matched the inflation then it would be $360,000(2046)/BTC and the eggs would be BTC0.0028.
If the Bitcoin exchange rate outperforms inflation and is worth $1,000,000(2015)/BTC that works out to $1,000,000,000(2046)/BTC which is well short of 1 Satoshi being worth $1,000,000.
To reach 1 Satoshi being worth $1,000,000(2046) we would have $100,000,000,000,000(2046)/BTC; if we constrain ourselves to a maximum exchange rate of $1,000,000(2015)/BTC then the US dollar inflation rate would have to be much much worse.
Thank you.
I officially declare this question answered and I, the op, satisfied.