Or you could work on good rec709 display and rent cinema to see your work and adjust accordingly.
As Mazze pointed out it may not be reasonable to have projection if you do actual cinema or feature work
two or so times in a year plus really nice budgets on top of that as lamps need changing and calibration cost also.
This is the reason i have stayed on regular displays for now as working on features. Just have super precise
calibration and work on your experience as in time you soon know how things look in the cinema.
If your display is not 99% P3 it will probably render some errors also in calibration and may or may not give issues.
What i have also seen is that monitors and image chain wit different scope type can also variate in results
even if they are calibrated the same way. For example when i worked with my clients suite blacks had more detail
in cinema and from my setup everything lined up more as i see on scopes. The issue could come from how they did dcp
but if i assume they did it correctly i would blame the scopes.