The problem with motorhomes is that once you’re parked, it’s not that convenient to just zip off and explore surroundings. The thing is just too big clumsy, and everything inside it has to be secured before leaving. To solve this problem we had originally planned to rent bikes, but that turned out to be really expensive. So we instead stopped at a bike repair shop in Auckland and asked them for the cheapest bikes they could dig out. The things only need to last for a month, and we weren’t going to do any long bike trips, so pretty much anything would do.
So, we ended up with 1 adult bike, 2 kid bikes, and 1 scooter.
The adult bike is pretty good quality, the other three look like something you’d dig out of a junk yard (which is pretty much what we did). But they work! And boy was that a good investment. We use the bikes almost every day – to play around, to explore the surroundings, to go shopping, etc.
When we get to Christchurch next week to fly out of New Zealand we will probably give them away to somebody.
Big Family Trip 
Nice idea! We are thinking of going to Canada this summer and renting a motorhome to drive around for a couple of weeks or so. Maybe we’ll copy your idea.