Once to get back to the topic.
I have just discovered in the Club website by accident that the current lease for Dens Park is 25 years long and commenced on 1st June 2016. https://dundeefc.co.uk/news/dundee-f...d-31-may-2016/
By my calculations this means that the current lease ends on 31st May 2041.
There is no mention of any break clauses in the lease so it is possible that it would have to be paid in full even if the new stadium was built at Campy Nou resulting in Dundee FC leaving Dens Park.