I have a wool suit that fits in every area except the waist is maybe 1/2 an inch too tight, but there's no extra fabric to be let out.
So is there any way a pair of wool slacks can be "stretched" without damaging them?
OP - I don't know if this is the solution, but I wanted to add a question to your question and perhaps the answer would be helpful:
I've been thinking about making some golf pants with an extended waistband which is made of some 10% spandex material to give the overall waist a bit of elasticity - has anyone tried making golf pants in this way?