With iPadOS 26, Apple added a dedicated Phone app to the iPad for the first time. It doesn't turn the tablet into a standalone phone, but it gives you access to your iPhone's line through Continuity.
You want to use AI on your phone, but you're stuck in a dead zone. Typically, that won't work, as those large language models require an internet connection. Aah, but wait. Google has cooked up an app ...