The last time it ran we had the assessments and then if successful we then had to do a video interview. Can't really remember the timescales between such but I think it was around two weeks from getting the invite to assesment centre to going to the assesment centre. I did an Airbnb which didn't work out too expensive - hotel is a little more.
I believe last time approx 500 were given the latter video interview, out of those approx 160 were brought to assesment centres. I'd hazard a guess that they'll just cream off the top assesment scores, and from that THEN look at your video interview, only if your assessment scores are high enough in the first instance.