Until you can buy oil without dollars. This was an explicit agreement called the Petrodollar system, which was premised on the US navy securing international trade. If the US navy proves unable to do that (and exhausts its arms and demonstrates unpreparedness for future conflicts) then the whole premise falls apart.
You might also stop buying real estate if the government seems unstable and economy is poised to collapse. Good soybeans also depend on fuel prices and the continued flow of fertilizer...
Or until you don't need to buy oil at all. China has reduced its consumption by 1.5M barrels/day this year alone.
Until you find a more thrustworthy stewart of the international order. Everyone yells loudly about how bad the us is, but then you realize that the whole world voted with there feet that every other alternative is worse. The russians tried for years to write some replacement fiction into reality (BRICS) even though they would be the first to get shanked if the old great game returned. Its a absurd situation where empire cosplayers long for the times of "greatness" while struggling on even small "to real" acts ..
"$20 Billion Oil Deals Paid in Chinese Yuan, US Dollar Left Out"
https://watcher.guru/news/20-billion-oil-deals-paid-in-chine...
"China and Saudi Arabia Settle First Oil Trade Using Digital Yuan"
https://www.economywatch.com/china-and-saudi-arabia-settle-f...