Hello Anna,

Thanks for your great question! There are a lot of perennial vines to choose from.

Merrimack county is hardiness zone 5 perhaps even a zone 6. When you look for perennials, the tag lists the zone that the plant is hardy to. The zone number gets smaller the more north and colder you are. Therefore, a zone 5 plant is hardier than a zone 6 plant.

That having been said, pollinators are your next consideration.  Native plants serve more native pollinators than do hybridized fancier plants because they have co-evolved.  However, you can look for vines with flowers that are tube-like or simple open construction, that most bees, butterflies, and hummingbirds can access.

A suggestion would be the trumpet honeysuckle.  The monograph at the link below, describes a variety that is behaved in NH and is available at native plant nurseries nearby:

https://mortonarb.org/plant-and-protect/trees-and-plants/trumpet-honeysuckle/

But please be careful, there are some varieties of honeysuckle that, though beautiful, are aggressive. Some will grow very quickly and well and you'll never be able to walk through your garden entrance arch again. That happened to me and I had a terrible time removing it. So look up the Latin name on the plant you are looking to by and see what you can find.  Missouri Botanical Garden

https://www.missouribotanicalgarden.org/   is a reliable resource.

Another great suggestion is the Woodbine clematis. This is what I replaced my aggressive honeysuckle with, and it grew very well for me in Rockingham County.

https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=a379

It's slower growing but perhaps you could plant one on each side of the arch.

Finally, here is a fact sheet from UNH Cooperative Extension that lists native plants in general and what value to wildlife each has.  It may help you identify some plants already in your yard that are good for pollinators:

https://extension.unh.edu/resource/new-hampshire%E2%80%99s-native-trees-shrubs-and-vines-wildlife-value-chart

For more ideas: https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/visual-guides/ornamental-vines

I hope that this information is helpful! Have a wonderful rest of your day.