Thank you very much! Let’s just hope it’s not a pricey alteration as I’d have to do it to about 6 pairs ?Rick may be able to tell you exactly how much you can let out in the seat. I let out the waist and had the seat taken out at the same time.
If I recall correctly it was on a pair of coverts from last season that didn't have too much give in the fabric. Worked like a charm.
Good luck and report back!