Welcome to the forum, episodezero.
My own take on Carmela's remark is that it represented a somewhat different, more romantic or optimistic concept of her character by Chase in season one than he eventually settled into for her. She like the other characters were not written in stone when the series started but were evolving in the mind of their creator as things progressed, and his mind became influenced, I'm quite sure, by audience feedback, though perhaps not in the usual way.
Chase has been openly disappointed that much of his audience actually LIKED these people in the first couple of seasons, and that very obviously (to me) resulted in darker and more cynical views of practically everyone as the series progressed. He was essentially saying, "Okay, I dare you to like them now!" The Tony of season one is much closer to feeling and expressing empathy than the Tony of season 7 (with the short-lived exception of his post-shooting "everyday is a gift" outlook of season 6). And the Carmela of season one is also much more concerned with Tony's soul and moral redemption than she is in later seasons (College is a prime example of this genuine concern of hers). Concomitant with her greater "love" for Tony early in the series was a lower priority on sustaining the materiality of the mob lifestyle. So I don't think she was in any way insincere or crazy when she was very attracted by and open to the witness protection offer after Tony narrowly escaped assassination. It's just that that Carmela was a different Carmela than the one we saw later, especially in season 5 forward. And I don't think the change was entirely organic but more of a reactionary move by Chase to make the characters as unlovable as possible.
Tony, his spirits crushed after b-lining to the fridge first thing in the morning: "Who ate the last piece of cake?"