We are in New England not as cold as you but close.I never recommend inserts that come with jamb liners they are drafty.Replacement windows that come in there owen frame are a better choice,much like a pre hung door.You my need to adjust your humidifier when you install energy efficient windows,because they are tighter then old drafty ones.

Here is a link that might be useful: alside windows

I asume that if you can use sash replacement you have double hung units. I don't believe that the humd. in your house had much if anything to do with the seal failing. Sash replacement is not going to be as tight as a new unit. However you can ad a storm screen combo. That will help alot to warm up the temp. of the inside glass which will help reduce condinsation on the unit. You might get some on the storm from leakage around int. sash. Most vinyl replacement units do not have combos so will glass will be around 30% warmer so 30% less moisture on unit.

Actually, we have casement windows. Based on the 3rd and 4th window salesman I have decided we need to replace the entire window mainly because of glass loss.

The new questions are:
Will I be happy 10 years from now with Vinyl windows? And if so how makes the "the above average" vinyl window.

What truly makes the window durable so that I don't have to go through this again for 20 years.

Thanks again.

There is quite a lot you need to understand about windows before you talk to someone about pricing. First, be very careful of Pella and
any other roll formed clad window. The roll formed cladding traps moisture against the wood sash and rots them prematurely. You should
stick to an extruded clad wood window or move to a fiberglass or vinyl, given your location.

You also need to consider the long term implications of Energy Star qualifications, SHGC, Visible Light transmission and how these
relate to daylighting and energy usage. Since we spend about 30% of our energy budget, understanding these issues could save you a
bundle of money over the long term.

I would start with Efficient Windows.org. From there I would see this web page that explains how these
factors interrelate: >Solar Heat Gain (SHGC), Visible Light Transmission (Vt), U-Value and Daylighting.

After that, make sure that you get pricing from several manufacturers lines. With the businees in such poor shape these days, you are in control, do not be afraid to move on to another source. Get 50 prices if you
need to, but get educated first and understand what you are buying and get a thorough, complete written specification and scope of work
from the contractor to make sure that he is quoting you the right thing and not setting you up for a giant change-order.

Casements are much more energy efficient than hung or sliding windows due to much lowere air infiltration rates. I would look carefully at replacing your windows with casements. And if you got a bad feeling from your interaction with any salesman, trust your gut
and move on.

Here is a link that might be useful: Understanding Vinyl Windows