Gents, thanks for your quick replies (and sorry for my slow one!).
While Blackwelder does have somewhat more feedback to its name (only positive), it seems like you were quite right, Steve, that most prefer bags at low temps.
Having browsed around a bit more, I'm now leaning towards a KG Sawatch, which some have used at low temps. Will post new thread to tease out the last bit of info before pulling the trigger.