5 brood is ok this time of year, though obviously the colony really struggled, preferably if you can insulate above the crown board do so once settled for winter so the least heat is lost from the top as possible. They will need 30- 40lbs of stores to see them through to spring so you will need 7 or 8 brood frames filled with stores if BS deep or 6 -7 for 14 x 12, one can feed well in to October so there is time for stores to be laid up.
Remove the super unless you use it as an eke for fondant feeding.
It sounds like they have some stores but not much so from you description one can guess maybe about 6 or 7lbs, you will need approx. 30 more lbs of stores. 5kg/11lbs of sugar mixed with 6 pints hot tap water will make up approx. 13.5 lbs of stores so they will need at least 10kg of sugar, 12 - 14kg more likely.
If feeding fondant don't faff around with little amounts above the feed hole, simply place a whole 12.5kg box on top of the brood frames inside an eke (in total they will likely need 1 1/4 - 1 1/2 boxes as feed) leave the fondant as it is wrapped up and make some cuts in the bottom for them to access. If a deep eke play some insulation PIR under the crown board (CB), if not a deep eke place the PIR on top of the CB.
Also if going the fondant route I would be inclined to leave maybe 2 empty frames and then dummy down and fill the rest of the space so heat isn't lost. if they fill those frames then add one more at a time moving the stores out and placing the empty (drawn if poss) next to the brood to fill up.
