Hand-sewing should be fine on polar-fleece, but remember that it stretches in at least one direction, so make sure that your stitching accommodates that. How about top-stitching in blanket-stitch with a fancy thread on overlapped seams? Some photos when you're done?
2 cows, 1 steer, 1 calf, 2 milking goats, 2 Romney wethers, 2 of Inger's ewes, 4 alpacas, 5 large horses, 4 minis, 30 chooks, ducks, 2 turkeys, 2 pigs+ 1 piglet, 2 dogs, 4 cats, bees & 7 humans!