Suppose that US politicians want to fund a moon mission without SLS, using only hardware that is working now in 2019, using Orion together with some future moon lander supplied by the private sector.
What are the feasibilities of and challenges to the following scenarios?
Could multiple Delta Heavy and Falcon Heavy missions pre-stage food, fuel, water, air, and supplies in low earth orbit, lunar orbit, and on surface of moon?
Could an Orion command module said lunar lander be brought to LEO separately then crewed (via ISS) by Soyuz, starting the crewed lunar mission from LEO?
Or instead, could said lunar lander and command module rendez-vous in lunar orbit? (yes this is assuming that orion and some miracle moon lander is made for this mission)