You may want to consider going to a single pane window. Dual panes will always leak with time, even the honest companies that reseal dual windows will tell you that. Dual pane in RV's is not very practical. I can't recall the name of the company, but I believe they're in Colburg OR in the old Monaco facotry. They can reseal dual panes, or replace them with thicker single pane. The cost is about the same, and you never have to worry about sinle panes getting foggy. As far as insulating value, there's not a lot of difference either. Let's face it, you have one huge non dual pane window going across the front of your motorhome, so all these little windows that are dual pane aren't really accomplishing a lot.
Brian
