How do I connect iPhone to iPad w/o hub and w/o cellular?

I want to control an iPad Keynote via Keynote Remote on an iPhone, but without having to worry about a hub or cellular.

Both devides can send and recieve wirelessly. Is it not possible to connect the two without lugging around a WiFi hub, hassling a client about their WiFi connection (usually not possible for a stranger like a traveling rep) and without having to have a reliable cell tower nearby?

If it can't be done directly, would an Apple TV work?

Thanks