iphone x battery replacement

Hi everyone - wanted some thoughts from you. My husband and I both have the iPhone X which we purchased last December. He is potentially upgrading to the XS and I’m not. I wanted to take over his phone because mine have a couple of scratches on the screen and his don’t (pesky earrings). Anyway...

So my battery on my iPhone X has absolutely been trash recently. Apparently 7 mins of iMessage use took 48% of my battery a caused it to drain to 30% form 98% over night. I am taking it to Apple next Friday, as they most likely will have to do a battery replacement. If Apple insist of keeping my...