those recommendations are all North of the River and O2 is south - so you would want to stay near the jubilee line which doesn't always run at the weekend and if Blackwall tunnel has a problem it is a nightmare and can take hours to get through.! You should google places South of river Blackheath has the Clarendon which is about 6 miles away - there are b&b's in Greenwich which is about 6 miles away but you are on the right side of river - I live south of river 3 miles from the dome and it is easier driving home this way as you wont get stuck in all the traffic wanting to go through the tunnel again! North Greenwich is not on the Docklands Light railway only jubilee line so you would have to go to Canning Town to change lines
Don't stay in Woolwich as it is a toilet and I am not sure there is anywhere there to stay -