As mentioned above, you don't need to retype:

        $ foo bar baz<cr>
        ^P^A<esc>u
        $ FOO bar baz<cr>

As for ^T, I'd wholly forgotten about bind, inputrc and all that- but of course both your proposal and the above can be put into an inputrc macro and bound to a key. However the all caps version is shorter when you remember you need sudo in the first place ;).