Hertfordshire to Gravesend

[Ryans1234]

Hi guys, I'm going from Hertfordshire university and going back to Gravesend tomorrow night/morning (Sunday at 1am) i am aware both crossing, dartford and Blackwell tunnel close, I'm a fairly new driver and this is the first time I'm travelling like this, how would I get back to Gravesend as it seems that Google maps doesn't tell me that the roads are closed and show me alternative routes home,
Thank you