My Beaver had a block heater (freeze plug type) installed when I bought it. That type of heater is available online. Google it and you'll find 'em. Mine also had chains, saving me a bunch of money! Check your rear tire size and Google tractor tire chains and you'll find those. There are also some dealer who monitor the forums and may chime in with parts availability and advice.
Don't know where you're located, but I'm in Pennsylvania and even with our relatively mild winters the block heater is almost a necessity!
John