Bought this fleece at the Harrogate stitching show in 2018. James' pair easy enough - just his baggies pattern with a bit less ease in the front and back (so there is not too much super thick fabric all bunched up). But I was guessing for mine. Some problems with the back crotch. It fits well when just standing, but pulls down as soon as I step up a step (as I had to for this pic). The sticky nature of the fleece makes it worse I think. I hollowed out the seam, which helped, and then added pockets when helped some more but there is still not really enough fabric in the back to permit bending over, unless I pull the fabric up my thighs when I sit down. I guess the side seams should be looser.
Anyway, these trews are also cat magnets which makes them even warmer!