I generally don't like making nucs later than June, however a July nuc can winter very well. My biggest problem with July nucs is that it is right in the main honey flow, and they fill up with honey before the queen gets a chance to lay. I use a 2 story five frame nuc to winter them, and have had success with both outdoor and indoor wintering, however prefer to have them inside. You can make them later, just make sure they have enough bees.