Hi there,
I think you're being too 'keyword focussed' here. Google doesn't rank keywords anymore it ranks 'topics'. So the first thing I might do would be to remove the local identifier in your research (not on your page). So you might get more info about bike tours. I mean they are going to be fairly and broadly similar wherever they are in the world. If you're talking about a specific location then google will know about it if you make sure that the location is in the URL and in the H1 and mentioned in the copy etc.
But I see your point, Answer The Public and LSI graph have pretty limited choices about bike tours and they are mostly just relating to different parts of the world. So go low tech. Think 'what do my people want to know about bike tours in Provence?'
Answers I can think of off the top of my head might be:
Things to take with you, what to do in an emergency, great villas and wine stops, how long is a good day's biking without fatigue for different ages, families vs couples, what are the best bikes? bike racks for my car if i'm driving? What if I want to fly and hire a bike? Where are the best places to stay.
Google loves comprehensiveness and is like a library so it likes organisation. So I'd be tempted to divide my site into main topics like couples, families, wine enthusiasts, fitness fans, stag parties, whatever are the general groups of people you have. and then include subtopics like the best bikes, ways to travel, places to stay and other elements of the tour to suit each 'customer avatar'
Go low tech, speak to your customers, use your own expertise on the topic. Tools are great but some of the best positions and number one position articles I have were just really comprehensive and well ordered, nicely written and super helpful pieces addressing a topic or group of people. So like a customer avatar.
Then at the end of each page have an FAQ and that will pick up all the long tail keywords and questions that will appear in blue in the SERP and increase your click-through-rate. Rankbrain is smart and you don't need to think about keywords anymore so much.
Just think about organising the content and covering all the bases with FAQ'a and you'll rank just fine. Even with a low domain and page authority. I have 'Veneers Cost' which is one of the most valuable dental terms imaginable in the number one position nationally here in the UK and I wrote the article before I knew a thing about SEO. I went around my dentists and asked them all what they thought and gave a no BS assessment that helps people find out how much veneers cost and makes useful comparisons rather than tries to get them in for a consultation. Watch Rand's WBF on searcher task accomplishment. That might help you. Good luck!