Hi Lochan
Symptoms sound very similar to what I've been experiencing for the last few weeks - the misting only occurs in cold or damp conditions & is mainly on the drivers side.
I drove over to Perth on Friday night & left the Bongo parked up at my other-halfs over the weekend. Came to start it on Sunday night & the Coolant Loss Alarm gave a much longer than usual beeeeeeep. The coolant level was down a bit in the tank, so I topped it up & drove half an hour to my mothers house. Leaving the engine running I popped up the drivers seat & had a look with the torch. The hose leading out of the engine was leaking from the joint & was blown up like a balloon

Not much I could do about it, so I drove the 100 miles back to Lochgilphead with an eagle eye on the temp guage & coolant alarm while praying that the hose wouldn't decide to bust in too inconvienent a place

I made it back ok & new pipes + radiator are now ordered (should get them to the back-of-beyond by Christmas...). The radiator's not connected to the leak, but was on the agenda to do anyway. Hopefully this should sort the problem out....