Will another church replace the Adventist Church?

I did a computer search for the phrase “look for another church” and came up with nothing. But your inquiry reminded me of a statement from Mrs. White, found in Selected Messages, book 1, page 179:

You will take passages in the Testimonies that speak of the close of probation, of the shaking among God’s people, and you will talk of a coming out from this people of a purer, holier people that will arise. Now all this pleases the enemy. We should not needlessly take a course that will make differences or create dissension. We should not give the impression that if our particular ideas are not followed, it is because the ministers are lacking in comprehension and in faith, and are walking in darkness.

In a similar vein, she wrote,

Satan will work his miracles to deceive; he will set up his power as supreme. The church may appear as about to fall, but it does not fall. It remains, while the sinners in Zion will be sifted out—the chaff separated from the precious wheat. This is a terrible ordeal, but nevertheless it must take place. None but those who have been overcoming by the blood of the Lamb and the word of their testimony will be found with the loyal and true, without spot or stain of sin, without guile in their mouths. We must be divested of our self-righteousness and arrayed in the righteousness of Christ (Selected Messages, 2:380).

I cannot be certain that there is no statement from Mrs. White along the lines you have asked for (though evidently not with just those words), but I was not successful in finding one. Perhaps one of the statements I gave you will meet the need. I hope so.

See also the two preceding questions and answers.