How many is church?

Church has been on my mind recently. We are currently going through a series called Just 10, based on the 10 Commandments and last week's sermon was on the Sabbath. The style of the services is very up-beat and contemporary, fast-moving and high-action. By the time I've squeezed in a long run I am rushing to get there on time and there are often a number of people to speak to and I arrive home at midday feeling frazzled. This does not seem to me to be sabbath rest. I do not find it possible to comtemplate, to sit in silence or to be still in the style of our morning worship.
When I run I often listen to a talk from another church down-loaded onto my phone or I listen to, and join in, worship songs. I marvel at God's creation and I pray in the silence of an early morning park. Does this not contain something of church?
Last Sunday, we went for an outdoor picnic with some friends. There were four adults and four children: we laughed, we enjoyed nature, we ate together and we talked, a little, about God. Does this not contain something of church?
But in mentioning this to one of the other adults, I was told that this was unbiblical. I suggested that what we had done was church, but was told that it was not: there were not enough of us, we had not worshipped, it was different in context and intent. I disagree.
I have decided that I will choose to do something other than our usual Sunday service some weekends: I will go on a long hike in the Surrey Hills, or a lie-in and still have time for a long run. Jane's recent post on Church at Home has added to my thinking: how could we as a family do church differently? I would be sad to loose the friendships I have at church; I love our corporate, lively sung worship; the teaching is frequenly relevant and challenging but I am missing something. I think that thing maybe a connection with God and I am prepared to seek Him elsewhere.