Devon looks manageable on a map. On the road, it is a collection of distinct areas joined by routes that do not always run in the direction you need. The A361 makes Barnstaple and South Molton relatively workable for each other, but it does not make north Devon convenient for Dartmouth. Likewise, someone in Tavistock may find Okehampton practical while Sidmouth is not.
That is why a useful search begins with travel time, not a county boundary. Think about where you already go for work, shopping, family or a weekend walk. If you are near Bideford, that might include Barnstaple, Great Torrington and parts of the coast. From Totnes, your natural area may take in Dartmouth, Kingsbridge, Ivybridge and villages across the South Hams, depending on the roads you are prepared to use.
A smaller dating pool you can actually meet is worth more than hundreds of profiles at the wrong end of Devon.
Keep your first search fairly close. You can widen it later, but starting locally helps you judge whether a conversation could become a normal part of life rather than a recurring travel commitment. Browse Devon singles by local area and pay attention to the stated town, not just the word “Devon”.