RE: How many planes do you take to the field?
At least 3 glow, as many as 5. One or two electrics as well. I can fit a lot more into an E250 Van!
If my son is with me, we will probably fly at most 3 of the glow planes. If I am by myself, I will fly no more than 2. It all comes down to what I feel like flying when I get to the field based on weather conditions, how crowded the field is and potential frequency conflicts (I hate waiting for the pin!).
It is usually pretty windy at our field, but towards the end of the day the winds sometimes calm down and we can fly the electrics while everyone else is cleaning up.
Picture below is from a day I "traveled light"!