Just went through this with our new build, I'd love to look but the pics are too small. Can you repost?

Vkilpatrick! Thx for your interest! I hope this pic is better. Really want to know what you'd do with the space. Not really interested in changing the size of kitchen...

I would change a lot about this space. For sure I would keep the pantry and the mudroom completely different rooms. I would put up a wall between the words "mud" and " room" on the blueprint. Put the door to the pantry where the fridge is now and move the fridge to the corner along the ext wall down the counter from the stove (be mindful of the way the door swings).
Change the way the door swings from the garage or else you will have to awkwardly walk around it to get to the bench and you will bump people sitting on the bench. I like the spot for the bench. Then the place you have currently have designated for the pantry can maybe be a walk-through closet with bars on either side?

You only need one pocket door.

If you put the wall up, you will also have a ton more space for cubbies or hooks on the new wall.

Dishwasher beside the sink is a good choice, from a plumbing perspective.

If you keep the bench under the window, you can put shelves on either side so it looks like a window seat, very cute. Colourful little roman shade on the window and some funky fabric on the bench. Storage for shoes under the bench.

We live in Canada too, (Kingston, Ontario) so I get the cold winter consideration. I don't think you want to expose your kitchen to the cold air near your garage every time you access the pantry, so I think the two separate rooms would be considerably more energy efficient.
Consider also the placement of heating vents on the floor in the mudroom, it's nice to be able to use them to dry mitts. If they are building a built-in bench under the window, I bet they plan on a vertical vent on the bottom edge of the bench. It would look nice, but I really love be able to dry our kid's boots and mitts over a vent on the floor!

Very good suggestions from vkilpatrick. The current mud room looks like a lot of wasted space. I am sure the woman of the house would love the big pantry as suggested.

I wouldn't ask the builder for the 'Optional bench'. However, it can be done later keeping your needs in mind. The area could be more of an entry coats on one side and seating on the other.

Depending on your family size and number of guests, think about 2 dishwashers. It also means that you can have one dishwasher with clean dishes and the other dirty and ready to wash. You just got rid of having to empty the dishwasher daily :).