Didn't drop quite as far as I thought it might but I think it looks like it's a question of when, not if, it goes sub-300k now. The trouble is too that with episodes nearer the two hour mark if people are prioritising a rivals reality show or miss episodes for whatever reason it isn't easy to find the time to catch up, so that audience just isn't going to build.
Not in the can but commissioned - though nothing they can't get out of like the announced BBVIP2.
Million Dollar Island have been very clever in selling it around the world as the "next big hit format" before it actually debuted on air because it has been far from a hit for it's premiere series in the Netherlands. It's getting absolutely thrashed in the ratings - goes up against Farmer Wants a Wife and gets less than a quarter of it's audience.