For the 2022 Montana 3791RD, the standard window sizes for the dining room slide-out are approximately 71.25" to 72" wide, typically a large panoramic window. The bed slide side window typically measures between 24" and 30" wide. The OEM dual roller blinds from Irvine come in Black Sun Shade (day) and Black Linen (night) materials, matching your current setup. Since exact measurements can vary by unit, it is important to confirm whether you need overall frame dimensions or internal tray dimensions to ensure proper fit. We also offer replacement Irvine springs in 1" and 1.25" sizes if you prefer repairing your current blinds instead of full replacements. Shipping to Alberta, Canada is available; however, please note that large items like these blinds may incur higher shipping and brokerage fees. Contact us for a specific quote including shipping costs.