Absolutely bring a backup charger or battery pack, but if you forget, you should be able to keep your device charged.
We expect big improvements with each new generation of phones from various manufacturers. The industry is at a point where there isn't much more that a smartphone can do – our personal devices already ...
Anker's MagGo 3-1 wireless charger is an ultraportable device that's dethroned even my favorite travel charger.