I always get one of those Starbucks Traveler 96 oz insulated coffee urns and it keeps the coffee pretty hot for a long time when traveling or even just to take with me to the office.
I hate the office coffee so I always buy the Starbucks Traveler and it keeps the coffee hot for quite awhile.
The coffee stays pretty darn hot for a little over an hour but is still warm enough to drink the coffee after 2 hours.
I drink a lot of coffee at the office so I drink all the coffee before it gets too cold anyway.