Edit G-code to change print order of multiple one-at-a-time print jobs
You can open the G-code file in any text editor and copy-paste the relevant sections of G-code to reorder them. It will be fairly obvious where one object ends and the next one starts because the printhead will move back down to Z=0; you can do a simple search to find the commands that move to Z=0 (in my version of Cura, it inserts a comment ;LAYER:0 at the start of each object).
To ensure that the extruder starts in the correct position, look back at the previous print (in the original order) to see where the extruder finished, then insert (at the start of the new print) G92 Exx.xx where xx.xx is the previous position of the extruder. If looking back to the previous print is too tedious, you can also just use the very first extruder position in the print itself and use that. It will just skip printing the very first section of brim/skirt, which doesn't make a big difference.