Originally Posted by
blitzen
Hi,
I plan to either travel to Minden ( shorter) or Hannover (probably better connection) and rental car from there
Book a comfy 1st class advanced ticket seat on an ICE if you can get a suitable price.
I would leave at least a 1,5 hrs gap in case your flight is delayed, but maybe even two hrs. I have flown both to DUS and FRA tens of times to catch a longhaul train mostly to Berlin so this is based on both experience and respect of Murphy's law.