tried tracking down info on how cold is too cold for HDPE.
so far all I’ve found is the glass transition temp for LDPE.
not sure that it translates well into real world performance, but it’s enough for me to get some samples and experiment. Certainly suggests that Polyethylene is my best bet.
http://www.appstate.edu/~clementsjs/polymerproperties/plastics_low_temp.pdf
Edit: although now I know I’m looking for the glass transition…
UHMW PE …becomes brittle at temperatures below −150 °C (−240 °F)
and
HDPE Properties:
Flexible, translucent/waxy, weatherproof, good low temperature toughness (to -60’C), easy to process by most methods, low cost, good chemical resistance
so perhaps kicking that bucket isn’t such a big deal after all 