IMO week long camps have little value. A week of training and working hard is fine but a week is just not long enough. If the things learned and the training techniques can be carried out over a much longer period of time, ok, but a week or two means very little. Exponentially better are summer long training programs where hockey specific training is provided.
In the Twin Cities, there are several excellent options like Velocity, First Athlete, OS -- don't mean to leave out any other worthy programs. A program should include skating, weight training, plyometrics, shooting, maybe a skating mill and a conditioning program. Team that with a summer league to help stay sharp on the ice and thats the way to go. The costs can be high, I guess -- my D has done both Velocity and First Athlete in different summers for about $1000. I guess that's not too bad comparing travel costs to go to a week long program in anywhereville USA/CAN.
Power skating programs are also very valuable. Pick out a good one and I assure you you will see NHL and college men players there. If those players can improve their skating, certainly HS and college girls can as well. I believe these programs are under utilized for their overall value.