So I took in the sleeves of my quasi-trench coat. I say "quasi" because real trench coats are made of specially treated cotton or wool, and mine is made of the same material as the Pumpkin Princess's windbreaker. It's great as a grown-up windbreaker, and also during cedar pollen season (the pollen shakes off more easily than regular cotton or wool).
I tried the coat on, very, very pleased with myself...until I realized that the sleeves on the cardigan I was wearing were too long, and a good 2 inches showed from the cuff of the coat. I suppose I could wear it with the sleeves of whatever I'm wearing underneath rolled up, but that usually only works for the first 10 minutes after I go out the door. So it's either bracelet length sleeves (3/4 sleeves for you normal sized folks), or altering the sleeves on all my sweaters.