How much comb have they drawn? The package bees were about 2-3 weeks later this year than last, and the nectar is already flowing in the valley. Last year, it was pretty much over by July, and although cooler this year, I imagine it will dry up about the same time. Once they start getting some growth, and can put some bees in the field, I would pull the sugar off and let em work for a living. Add a box when they need it, and reevaluate them about mid July. Depending on what they get done, you may be able to take some for yourself, or have to feed them to get more comb drawn, get their stores up for winter. I used the finski terrarium heater technique last year, along with drawn comb. I also boosted them with frames of emerging brood for faster build up. Ended up with a couple boomers and averaged 70 lbs.