If it is not too hot, or too cold, or rainy, I take my 25km/h EU-regulated e-bike for my 7km trip to work (40% public road /w bike lane, 30% public road /wo bike lane, 30% forest road; 110m altitude to climb one way, 140m the other).
I've average height&weight, but am not athletic - no chance I could do that route on a normal bike. So while it's not a huge workout, the bike doesn't go all by itself, and I really feel it has a positive effect on my overall health.
The additional 5km wouldn't make a huge difference with an e-bike (just 12m longer ride), as long as the altitude you have to climb isn't significantly more (you can check that on Google Maps).
Maybe you can rent a (proper!) e-bike from a specialist dealer and give it a try.
I think the biggest risk is not the ride, but the vehicles on the roadway. Way back when I used to ride 6.6 miles from home to the university, but stopped after the second time
I got run off the road. The bus was slower, but safer.
The additional 5km wouldn't make a huge difference with an e-bike (just 12m longer ride), as long as the altitude you have to climb isn't significantly more (you can check that on Google Maps).
Maybe you can rent a (proper!) e-bike from a specialist dealer and give it a try.