Yea, it's a big ask for Remco to pull this one off. It would, however, should he somehow do it, be a huge step forward in his progress. And even if he arrives with the best sprinting at the finish, but loses to Martinez (the most likely candidate), it would be the same for his career thus far.
Because if he can handle these climbs on the last stage of this race, I think he's ready to take on if only for experience the Tour. In fact, if he were to win this or take second place, I'd take him to the Dauphine and, based on his performance there, bring him to the Tour. By contrast, if he gets significantly dropped today, I'd stay with the Vuelta plan.