it seems quite feasible to have different start/finish locations;
- the riders are absent for ~48 hours, so the teams can easily pack-up, get some rest, then get over to Arrivée
- start and finish have very different requirements.
- for riders ... well I'm not sure it would be much more difficult. Maybe base yourself (e.g. hotel/left-luggage/family) near Arrivée. A gentle spin in the afternoon over to the start. Bike-check might complicate things ... but that could be done anywhere!
Still, quite a complicated thing to assess, given a long-history of a known working setup.