Hello Maureen
How delightful! To have a full 2 hours to luxuriate in yin-ness. There was a teacher who once lead a 12-hour yin class. You might get some ideas from him (check him out
here.
There are lots of things you could do. Pick a theme: you have time to spend 45 minutes on the spine and 45 minutes on the hips. Do the first part of the class on spinal flexibility and the second half on hip mobility. You could work through the full list of 6 lower body meridians: start with the Kidneys/Urinary Bladder through backbends, then the liver/gall bladder with twists, side bends and external hip rotation, then the stomach/spleen through forward flexions. So many choices.
With that length of the time yinning you may want to end with some yang work to pull the body together. Try some counterposes like the McGill Big 3 to tone the core, or the Golden Seed to firm up the legs and hips. Remember, these counterposes are not to gain more flexibility, you have already done that, these are for stability, stiffness and strength.
Good luck
Bernie