It may break possibly causing serious engine damage. When a timing belt breaks, the camshaft stops turning leaving some of the valves in the open position. The crankshaft, because it’s heavier, continues to rotate by inertia. In an interference engine, this will cause the pistons to strike the valves that left open. This may result in broken or bent valves, damaged pistons, and possibly, destroyed cylinder head. The damage will be less extensive in a non-interference engine but in either case, the engine will stall, leaving you stranded. God I love Google Hmmmm 7 day road trip, I wouldn’t risk it, I’d get it fixed before I left, nothing better for a trip then your car dying and needing some work done or engine getting destroyed and needing a new engine half way through your trip…. good luck