I have a 2005 JD 4110 ("MCUT", 20hp). I purchased it new. It currently has about 350 hours on it. Always kept indoors. It has a 60" MMM, but I have only used the tractor for mowing maybe 100 hours, probably less. My 5.5 acres was already cleared when I bought the property (neighbors referred to it as "the park"). The majority of usage has been FEL work (bucket/forks/grapple) to move "stuff" around, gather up downed trees/branches, and spread a few loads of dirt. Those tasks may come up less than once per year, but when they do, the tractor proves invaluable. So yeah, very low hours on a 20 year old tractor are possible, especially if not used regularly for mowing.
I'm seriously considering replacing the tractor with a Kioti CX2510 with cab, mainly for creature comforts. The 4110 seemed a lot more comfortable 20 years ago when I was only 50 years old.