re: The Time factor V the Delta V factor.
If it was up to me, I'd do long range expeditions by sending rovers, supplies, fueling depots, return propellants, instrument packages, shelters, and all the rest of that crap by slow-boat, two-year transfer unmanned landers (or orbiters, for things that need to stay in orbit).
Then when everything has arrived safely, and any "re-do" missions have been done, and the coffee is hot and the welcome mat out, send your crew in one red-hot high-Delta-vee module with whatever minimums are necessary for the trip.
Not the only option, but workable.