It's been nine years since flying the Dart (attatched to a 748) in the arctic, but I seem to remember the Take off trim settings for those marks of Dart were max 85% no matter how cold it was, and the southern Manitoba summer heat could require trims as low as 65%. Obviously our TGT limits would dictate a higher / lower setting through the climb and cruise or in emergencies etc.
Stone age FADEC. Set the trims properly and you could always firewall the throttles with no ill effects. (Hawker Siddeley and BAE called them throttles.)