CMC, been now 3 years, going again this year. In the school, walking distance across the car park field and your there. Unsure about the others in relation to access. Whether this could be a decider, it’s on school field so short grass, there is a section on the flat, which is closer to the activities and a gentle slope on the field closer to the school. In the 3 years of being there, the balloons at the 6am flight have always come over the cmc site. Avon group run it. We got lost the first year finding it and the CCC was a reasonable distance, across roads. I don’t know about the other options. I have email and telephone if you need it, just PM me. £38 for thurs-sun
We stayed at Baltic wharf a couple of years back and just stepped out the van to see the balloons with the Cottage Inn open serving coffee and sausage/ bacon sandwiches . Great atmosphere and we brought our own coffee. Mind you, all depends on the weather.
Been twice and stayed just on the farmers field at parsonage farm, it is just general camping so no real structure to how people park. The mcc areaa is same place just down the hill in another field. Great location and a few quid cheaper BUT watch out of it rains due to it getting water logged down there and getting back up the hill.
You won't get much closer for viewing ( subject to wind direction ) ..
Done 2015 and last year but think I have seen it all now, last year was disappointing with stalls and the funfair..
If you go with CAMC, take a torch with you for evening events.
Access is through a hole in a hedge, which can be hard to find on your way back on your own in the dark. It's a long hedge!
Should be plenty of space.