Blinds too short, though. By like a foot. They were the longest blinds sold so it's not like I'm an idiot and should have gone with the longer blinds.
So I went back to Argos and got another blind. These are cheap roller blinds, by the way. Also bought a glue gun. My idea is to cut up this new blind and then glue the pieces on to the existing blinds at the bottom. It will look like crap but it should work and I'm only here for six months.
The glue gun says that it works on fabric so this should work. It was £15. The other blind was £15 too. So in total this whole blind fiasco cost me about £100. But I own this stuff now. Sure, I've gone decades without needing a glue gun but who knows what tomorrow brings? And now I have shitty blinds in case I ever find a flat with no blinds again and requires these specific sized blinds.