Qualsiasi persona italiana direbbe "starò meglio" in un contesto del genere...
This is really a flaw of DL. Normal BE usage is: I shall, you will, he will, we shall, you will and they will. "I will" has much more emphasis, like in: Father to daugher: I do want you to marry him. and daughter responding "But I will marry him." The same applies to: mother to son: you don't want to go to school but you shall go.