We're only going to the next county. Tried a weekend last weekend and managed one car, but that was without dcs bikes and we'll need them. 2 DC (5&2), 1 large dog, lots and lots of stuff.
Last year we took both cars. Having a second was useful for quick trips to the shop etc...
We don't have a roof rack. I might get a trailer next year. Although wouldn't fancy Cornish lanes...