You can try the “hide toolbar” option. iOS 26 works fine for me on my iPhone 15 max. No real difference than before the upgrade.
Note that this may not work in Spain without a rifle attached to your iPhone.
I had used that before sometimes, but hadn’t used it since iOS 26 came out because it was so hard to find on the now cramped screen. I just now poked around and finally found it (it’s much more buried than it was in iOS 18). That definitely helps, but iOS 26 still places an up/down arrow and checkmark toolbar (I really hate these checkmarks that replaced “Done”) over the middle of the text entry window.