O79 -- I have had a winter coat altered (my dry cleaner/tailor did it for me) but I had it shortened in the hem and sleeves. See http://youlookfab.com/welookfa.....lterations
I'm not sure whether a coat can be let out. It's my understanding that the one thing on a jacket, coat, dress, or shirt that really cannot be tailored is the shoulders -- maybe "cannot" is not the right word, but it's generally thought to be too much of a production to make it worthwhile. Are the shoulders where the fit is snug?
In any case, be prepared to pay handsomely to tailor a coat. My two alterations to a lined coat, simple as they were, cost $60, and my tailor is quite reasonable. It was worth it to me, but not something I'd want to do very often.
