Is it possible to pack for two weeks or more just using your carry-on allowance? Of course it is, but you’ll need some expert packing tips to pull it off. I’m packing for a three-week trip to Australia – in a 40L backpack. I did the same when I went to Vietnam and Sri Lanka. In fact, the last time I checked a suitcase was for the US about 5 years ago. That was because I wanted to bring back some of my belongings I’d left at my parents’ house. For some, packing using only your cabin bag allowance sounds routine. But here’s the full disclosure: I don’t think I’m…