Welcome to the forum.
Unless anything changes between then and now, it should be on until mid-May.
There's a useful unofficial website that lists boxsets and their expiry dates here
NOW TV do very occasionally change these dates at short notice, but it's usually accurate.
Such a shame its ending!
Nothing lasts forever @TcKay. The TV series actually finished on the 23 May 2010 (ie: seven years ago) 😉