Durable tough cold weather performance plastics are easy to figure out. I have experience in the composite plastics industry for 40 years, off+on. My focus of interest is polymer composite pipes, but have also worked extensively as a shipwright boatbuilder.  Certain copolymer crosslinked blends of HDPE+LDPE+MDPE polyethylene resins have been used in cryogenic applications where very expensive fluorpolymer plastics are often used. Some types of -260F LNG cryogenic pipes and tanks are made with simple cheap plastics. Of particular note is the use and availability of GRAPHENE + Basalt Fiber reinforcing materials. In a nutshell, I know how to make this plastic boat bulletproof to a 50cal machinegun, at small extra cost.