You should also set up a couple swarm traps. Try to get some free bees. But don't bank on that get a couple nucs but consider swarm trapping as well. Also biggest thing to work out between now and when you get your new bees is what went wrong and what are you going to do different this time. Mite control early enough so that the last few rounds of bees are raised with very few mites around is vital to good winter survival. Follow that by enough honey or sugar syrup in the cells and capped over in time for winter. Finally depending on your fall pollen supply consider a pollen substitute to boost your winter bees protein stores. By feeding it to the previous couple generations of bees they will raise the larva in big puddles of royal jelly allowing them to really fatten up on protein reserves. Big, healthy protein filled bees and low mite counts are what makes long lived winter bees imo. Good luck