Not everything you need before a trip is a thing you pack. Renew your passport, buy insurance, print the boarding pass, that's a different list.
Separate from the packing list
Tasks live in their own list per trip, so your packing list stays about items and your to-dos stay about actions. Give each task a priority so the urgent ones stand out.
One place for the whole pre-trip checklist
Passport renewal, travel insurance, checking in online, telling the bank you're traveling, all the small things that pile up before departure, tracked in one place.