No kidding. Interstellar made $677 mil worldwide on a $165 mil budget. On a $225 mil budget, that would range from "just" in the green (barely profitable) to actually resulting in a loss for the studio.
Not saying he isn't capable of making a decent profit on a $225 mil original film that wows audiences because he most certainly is (it's Chris fucking Nolan), but that's a pretty tall order. On that note, he better have another Inception-level hit on his hands. It needs at least $600 mil just to break even (marketing budget and other expenses would bump its total costs to over $300 mil, plus theater take).
Lol, why are you talking as if his career is going to be in trouble if the movie doesn't end up bringing a profit? Christopher Nolan is of such caliber that he doesn't need to do anything anymore. Even Denis Villeneuve, a similar talent but a much smaller name in Hollywood compared to Nolan, received a big project such as Dune after Blade Runner 2049 failed to meet expectations.