Format=Flowed and Non-ASCII Characters

What's the best way to send text with non-ASCII characters, given the 
option of format=flowed? The obvious thing to do is to choose a charset, 
and encode it in quoted-printable. But at that point I hardly need 
format=flowed, since I can now safely transport lines of any length. Or 
should I use UTF-7 instead?

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Ashley Yakeley, Seattle WA