I doubt it's the bi-pod size and the snow can get kicked around. Most people don't get low enough and knees up enough from that postion with a bi-pod. Winter cloths also get in the way along with middle aged guts or beer bellys.
In your home do some back and leg stretching first. Then try it indoors everyday for a week. For right handed try placeing your left elbow outside your left knee then tucking the left hand under the stock to be used like a rear bunny bag. Your knees will be up and your head low.
If your phisically capable I gurantee with some stretching and practice you will be lower. If not, you probably should use sticks.
Thats the proper most accurate sitting position with a pod. I have to use it for woodchucks when the hay comes up.......and switch to the sitting pod in some fields rather than prone. And thats small targets at a long range. I have tried sticks which are nice for swing and close range but can not match the accuray of the pod in that position. You may not need that accuracy/distance for coyotes and thats why many use sticks plus it's easier to swing and more upright. But, for long distance where the swing needed is less because of the spread distance. I gurantee that if you can get in that position with a bi-pod it is more accurate that sticks.
Bi-pods are the most accurate practicle field tool from prone or sitting I know of, besides draging rests, tables or front bags along with you to the field. Which personally I would hate to do.........I go light or don't go.
From the sitting position bi-pod or off hand most don't tuck enough nor get low enough imo. As a whole wire'ie build people do better at it then stocky builds and guts will definately get in the way and keep one upright. You will feel the gut (if you have one) get in the way as soon as you try to get into the proper sit position......be it pod or offhand. The gut will open you up both vertically and horizontally from that position........as will not stretching .
