I had four wool fabrics to use in Audrey’s winter wardrobe this year, and I didn’t want to be stuck dry cleaning or even hand washing them. I cut a 20 x 20cm sample of each, and sewed a 10cm straight line of stitching in warp and weft directions (contrast colour, very carefully measured, and with backstitching at each end), I then washed them in a delicates washbag with my normal wash, and measured the stitching. I kept washing until they stopped shrinking. My normal wash is only 40 degrees C, so it wasn’t going to felt them. I kept a little chart of which fabric shrank how much in each direction. None of them shrank any more after 4 washes, and one only needed washing once. The one that needed four washes was a very loosely woven boucle.
So long as you treat the fabric before you cut it, you should be fine!