I agree with the above posts. Having been in the Drayton area I have seen what you are up against. I would write off the finer gravel you have put down, and I would pound the pitrun to it. 5-6" pitrun with fines and let that settle for a year, or just drive on it,then go to finer stuff IF and only if you don't turn muddy again. If the yard is still muddy, then put more pitrun in but go a little finer like 4-5"-.
22 years ago when I bought this place I had about 50' of driveway that I had to use 4wd to get through in spring. I pounded the bigger pitrun to that hole and the rest of the driveway for two springs, now I have a usable driveway and this year I am going to put down 3/4" granular 'A'.
After and only after you get a reasonably dry yard (no mud) I would go with asphalt grindings, but only if you can get them cheaply. Sometimes when road contractors do a shave and pave on the roads they have more grindings than they can use in the new mix design. When that happens they will sometimes sell them to locals, cheap.
Ok all good suggestions guys. Are you saying I should dig all my gravel up and then add the bigger rock? That would be very pricey to do. Can you put bigger rock down right now on top of the smaller 1 1/4"?