Welcome to the site.
Look for frames that have 17" or 18" between seat post and handlebar stem. Some datasheets have that measurement, some do not. Some vendors expect their product to fit all. Having short arms and legs myself (28" inseam, 30" sleeve) I argue with that concept. Unfortunately you won't find any small bike stock in stores except in megacities. Small bikes in my town have kiddie quality components on them.
Mid drives and geared hubs are the two styles of motor that can handle grades. Few mid-drives can be ridden unpowered, mainly Yamaha & one shimano motor. I have a geared hub drive like juiced sells, but it gets quite hot after I ride 30 miles with the 77 hills I have to cross. Many vendors in California quit selling geared hubs, possibly because they are not up to long uphill runs without overheating. I have short roller hills here in sou. Indiana.
Another important featire to have in mountains is disk brakes. Rim brakes IMHO do not work in the rain. Rain is not something the weatherman can predict in this area, it just happens. I'm 160 lb and I find 160 mm cable pull disk brakes stop me very effectivly, even with 75 lb of bike motor & battery & 60 lb of supplies.
If you can get to crazy lenny's in WI he has a huge stock of e-bikes. It is time for end of year closeout. You might call before driving to see if he has any small ones that don't have 20" wheels. I find 20" wheels are bone jarring on bad pavement. I ride 26" wheels with 2.1" tires, but no suspension. Suspension adds ~$1000 to the cost of a bike and probably limits the life to 5 years since the seals will wear out. IMHO.
Another low priced vendor of geared hub motors is magnum. They do have a few local dealers, check the website.