Try 'komoot' - designed specifically for cycling & hiking - plan your route on PC, then send it to the app on your phone for navigation. You get a free map of your local area to trial it, then it's about £8 to unlock mapping for a county or a one-off £29 payment to unlock mapping for the whole world. The route map is loaded into your phone memory; so works fine when you're in a no-signal area. Maps are: Open Cycle Map, Open Street Map, Komoot's own and satellite view.
Turn your next ride, hike, or run into an adventure with komoot. Get inspired by tapping into shared community knowledge and recommendations, then bring your adventures to life with the easy route planner.
another vote for komoot, it's worth the 29 quid world map lifetime one off,sometimes they offer it for 19 quid. matched with this,it makes a great nav solution. Diyife Bike Phone Holder, [Campatible for Garmin] [Detachable] Universal Phone Stand for Bicycle & Garmin GPS, 360° Adjustable Phone Mount for Bicycle Motorcycle Fits 4-6.5 inch Smartphone https://www.amazon.co.uk/dp/B08BJX5YXP/ref=cm_sw_r_apan_glt_fabc_PTCZ85C9T1M6RMDFK1N7?_encoding=UTF8&psc=1