I weighed my lightest basses, amp, and cabs tonight, and calculated the weight of seven different MROD combinations, listed from lightest to heaviest:
1. Baldwin short scale, AI Focus, composite Crazy8........27 pounds
2. Fretless P Bass, AI Focus, composite Crazy8..............29 pounds
3. Baldwin short scale, AI Focus, composite Crazy88.......37 pounds
4. P-Bass, AI Focus, composite Crazy88.......................39 pounds
5. Baldwin, AI, Crazy8 and Crazy88.............................52 pounds
6. P-bass, AI, Crazy8 and Crazy88...............................54 pounds
7. P-bass, Baldwin, AI, Crazy8 and Crazy88...................61 pounds
In reality, these numbers would be several pounds higher because I did not include the weight of gig bags, towel, bottled water, extension cord, channel strip, HPFPre, tuner, etc.
Given a double gig bag, it is conceivable that I could walk from car to venue in one trip using two cabs and two basses, despite my age.

If I broke the MROD rules and used a hand truck, it would be a piece of cake!
I've loaded-in in one trip several times with one bass, and one or two cabs, which is something I couldn't have imagined doing even 10 years ago, when a single cab weighed at least 50 or 60 pounds!
Baldwin short-scale 6 lb 5 oz
'73 P Bass............. 8 lb 7 oz
AI Focus 2R SIII..... 4 lb
Crazy8.................. 10 lb 15 oz
Crazy88................ 21 lb 10 oz
Cajon Bags (ea)..... 3 lb 15 oz