Good day, just want to share my experience,
I am using 2fa as my security in my emails and exchange accounts, so one day I nearly lost my phone and that phone holds majority of my pins, 2fa, etc. so I thought I lost all, luckily I found the phone. So now I'm thinking of buying an extra phone for backup. What else do you recommend for backup?
For me even if you have just one smart phone you can make a back up you can write in the note book, on paper and in your diary and keep it important to backing up your Private key or QR code and Gmail. So even if you still have the phone you can still access it using a laptop or computer you will not worry that others might get your bitcoin. But your plan is good too i'm just try to give you some idea how to secured your data. good luck!
Old ways still the best way to keep your back ups, this process even it will take time but what important is you still have control if ever that you lose your phone, buying another one for back up also can't assured you since there's also things to consider, what if your phone got damage or what if it was stolen from your house, same scenario that not too often to happen but also still possible, writing everything inside your diary or even in a notebook that you can kept inside your room or closet will be fine.