IMO this is your big chance to do a major upgrade for little trouble. As said above, two 24s is like 170AH at most, while two 6s is 225AH or there-abouts.
This is a huge improvement that you will really notice while camping. Changing battery boxes and a bit of wiring is totally trivial in comparison. Go for the 6s.
BTW Interstate has gone to Trojan for their 6s now so their 225s are really T-105s. If Sam's or Costco has these 225s for half price like their other 6s, that is a huge bargain!!! Trojan T-105s at maybe $90 just because it says Interstate on them? Holy Cow!