Was Elijah really the only one left?

Elijah says so twice at Horeb: "I, even I only, am left" (19:10, 19:14). He had said it on Carmel too: "I, even I only, am left as a prophet of the LORD" (18:22). But the chapter before had already told of others. When Jezebel killed the LORD's prophets, Obadiah hid a hundred of them, and he told Elijah so himself: "how I hid one hundred men of the LORD’s prophets with fifty to a cave, and fed them with bread and water?" (18:13). And the LORD tells Elijah, "Yet I reserved seven thousand in Israel, all the knees of which have not bowed to Baal" (19:18). The chapter doesn't say whether Elijah knew of the seven thousand; it sets his words and the LORD's side by side. Paul quotes both. He says Elijah "pleads with God against Israel" (Romans 11:2): "I am left alone, and they seek my life" (Romans 11:3). "But how does God answer him? “I have reserved for myself seven thousand men who have not bowed the knee to Baal.”" (Romans 11:4).