this was a fantastic sensory play activity. The children had to really push and Mould the lard and seeds. We used different seed sizes, nuts, grains and oats. Rolling them into balls was not hard and now we enjoy watching the birds eat them from our bird feeder.
These boots are sturdy not expensive and able to have wellie socks if you buy them slightly larger. http://www.viktorbuty.co.uk/en/468-ren-but-chaber.html
These boots are recommended in Russia and can go down to -18 http://www.bogsfootwear.co.uk/shop/kids-waterproof-boots-shoes