Actually it was incredibly difficult landing the blimp on this driving range. It was lined with trees on all sides (which cause mechanical turbulence, which makes landing more difficult). Plus, trying to land in a small field in the middle of the afternoon when there are a lot of thermals isn't easy.
Even when we are operating at an airport, we generally take off and land on the runways only if the wind is closely aligned with the runway. Usually we'll land in a grassy area adjacent to runways or taxiways instead. We almost always takeoff and land directly into the wind (there are several reasons for this).
As far as finding a field large enough, you just have to use your best judgement. Yes, we have published takeoff and landing distance/performance numbers, however, since we almost never takeoff and land on an airport surface with published distances (runways), you basically have to make an educated guess.
Even though we don't travel at fast speeds, I would never say that landing one of these things is easy, because it's not. There are a myriad of conditions you have to consider (i.e. how statically heavy/light you are, wind direction and velocity, size of the field you're landing in, obstacles, etc).
You've probably never flown an aircraft where you can have a 30 degree nose-down pitch attitude, zero indicated airspeed, and still be climbing at 500+ feet per minute.
LTA-Airship is probably the rarest category/class rating you can find out there. There really just aren't many airships or pilots who can fly them out there.