We fine-tune our plans from time to time. Mid-course corrections, as it were.
NASA has made worse investments than to review these threads. Substitute Space Shuttle main fuel tanks for our "enclosures," pack them with the comforts of home, and lots of green growing things, and put in a small crew of from six to ten people, and you'd have a legitimate Mars mission.
Nothing will substitute for the Nuclear Rockets. NASA may as well shout that fact out loud right now.
I vote to place you as a top adviser to those nattering nabobs at NASA!