Thanks for all your responses and sorry that I was unclear. I was actually asking 2 separate questions and after re-reading my post, I realized that it was confusing.

1) What is the best bicycle grease to use right now so that my son can enjoy riding for the next 2 months?
2) Also, what is the best thing to use when putting the bikes away for winter storage?

Looks like I got answers to both! Thank you all for your help!!!