At last I got round to watching "Crossbow". Fascinating. I was shocked by the man who said that Hitler planned to send 2,000 rockets PER DAY! I replayed the clip to be sure. A map in the programme showed abut 25 rocket launching sites, in France, so that would work out at 80 launches per day. That's over 3 per hour which could have been done as far as the actual launching is concerned but building rockets at that rate and delivering them to site would have been a formidable task. It seems a very big number. Imagine the devastation. London (and other cities) would have been like Berlin or Stalingrad.
Another worrying thing was that the only way to neutralise the launch sites was by boots on the ground and that was accomplished (after D-Day of course) just in time to prevent that devastation. And if the rockets had been ready even a coupe of months earlier, the D-Day landings (and London etc.) could have been wiped out. R V Jone's book "Most Secret War", and "Crossbow" showed that Linderman, later Lord Cherwell, Churhill's Chief Scientific Adviser, obstinately advised for some time that Germany was incapable of building such a large rocket so there was no need to target them, and was only convinced after being shown clear evidence. What with all that and the dicey weather on D-Day, we could have lost the war, even allowing for a bit of over-dramatisation in the programme. I wasn't fully aware of that. Whew!
A comforting thought is that Hitler was not close to having a nuclear bomb, but given another few years of war.......