14x12 so even with 4 frames filled, you still have a decent sized brood area available.
But yes, you need to give them access to the brood box for, errr, brood rearing!
First question is what is in those stores frames.
If it is just sugar syrup, then it is painlessly expendable.
If it were actual honey (even Ivy) and you had access to both a (very) well-regulated warming cabinet and an extractor that will take the jumbo frames, then extraction becomes a definite possibility.
Other possibilities include storing the frames for nuc-feeding and such.
Personally I would (but said without seeing your actual situation) -
-immediately remove one (the least valuable - your call) of the stores-only frames from each hive, and give them each one foundation frame, positioned between the brood and the remaining stores frames. A decent colony should draw it out quickly at this time of the year.
- then I'd uncap those removed frames and, in plenty just-warm water, I'd soak out the scrap stores over a couple of days to get an empty but drawn frame.
- once done (or nearly - the bees will finish the job) I'd return the empty drawn frames, and to make room, remove (and store, freezer, etc) the 'best' remaining stores frames from each colony. I'd arrange the remaining 2 stores frames at the back of the hive (if warm way) or one at each end (if cold way). And I'd put the newly-emptied drawn frame next to the last brood frame on the other side of the brood nest to where I'd put the foundation.
- this should give each colony two more frames available for brood pretty quickly and relieve the potential for congestion-induced swarming. And it leaves each colony a couple of frames of stores in case of bad weather, etc, and gives you a couple of frames of stores in reserve for contingencies.
