I couldn't find your Tesla comment so am quoting this instead. Rather than a Tesla purchase which depreciates the moment you punch it for the first time, how about buying a vacation rental home? For the same amount you'll save in 2.5 years of your off-site plan, DH and I recently provided the down payment on a new 3-bedroom home in a gated community in the Champions Gate area.
YMMV but our investment includes unlimited stays, free pick-up and drop-off at MCO, up to 16 days of free park entry, deeply discounted meals at Signatures for the Holidays, and use of a car to explore sites in Florida.
For you, it would be a source of income making all of your Florida travel "free." You appear to be a person who would always be able to find ways to enjoy WDW and Orlando even after your son is on his own... home versus Tesla - the home would be more fitting for you and your family.