The match will last for 5 days if West indies are able to show some good performance. Both teams will be playing after a long time and it will be interesting to see how they react to the conditions. England may have slight advantage as they have already played a warmup match recently and the series is going to be in their homeland but i will not under estimate the WI team this time.
Take a look at the West Indies squad and tell me one player who is consistent in the Test level, there are players that performs well in the ODI format in that squad like Shai Hope but to understand the real situation take a look at all the Test averages of the players that are in the squad and majority of the players average around 30 which is not even a standard in International cricket.
I too am expecting a complete white-wash but I want to see some fight from the West Indies team. I want them to at least drag the game to the last day. If it was one-sided it can be boring.
The only hope for West Indies in the Southampton ground is that they defeated England recently twice in that arena and that is the only confidence they can have going into this match, their batting line up is pathetic and good luck dragging the game till the fifth day against James Anderson, Jofra Archer and Stuart Broad.