Definitely fix it now vs. later. If it truly is a double row, simply cut one row off. If neither is directly in the middle of the bar, as it should be, you will need to decide if you want to cut both off and move one over and hang it from a masking tape sling. The bees will reattach it and chew off the masking tape. (this only works if the comb is empty or only full of brood.) If it's heavy with honey, harvest it.

If you don't want the work of reattaching it, just leave the off-sides single row of comb until spring and move it so it gets filled with honey vs. used for constant brood production.

 

All you have to do is just move your follower board into place next in line, or a piece of properly drawn comb to get the next frame drawn correctly.
As previously stated, get it done ASAP to save yourself trouble.

 

If you have lots of season left I would fix. If not leave it till spring. Depends what they have for stores as well.

 

If it is on the outside edge of the hive leave it till spring then remove it when the comb is empty and they can try again. If the comb is in the middle then try and sort it out. They need a lot of heat for comb building which they might still be able to generate further into the colony with sufficient bee numbers. Can you see them festooning when you inspect? Is the proprolys cracking when you seperate the bars or is it still sticky? These are questions you can ask yourself to tell if they are still able to build wax.