Well, it could be for love. In many fanfics, their relationship has been through a lot, and leaving together is a way to start anew, away from the prying eyes and pressures of Hogwarts and the wizarding community.
Perhaps she tries to find them right away. Using her intelligence and resourcefulness, she starts to search for any clues as to where they might have gone. She could ask other friends, like Neville or Luna, if they have seen Harry and Ron. And she might be determined to bring them back, not willing to give up on their friendship easily.
In fanfiction, it could be that Charlie has a more mature understanding of Hermione's intellectual pursuits. Ron sometimes struggles to keep up with Hermione's thirst for knowledge. Charlie, with his own expertise in his field, might be able to engage Hermione in more in - depth conversations, leading her to consider a relationship with him instead of Ron.
One possible reason could be a misunderstanding. Maybe they misinterpreted something Hermione said or did, and in a fit of anger or confusion, they decided to leave. For example, if Hermione was working on a project alone without consulting them, they might have felt left out and left in a huff.
If Ron and Hermione leave Harry in the fanfiction, it would change the entire fabric of the story. Harry would have to reevaluate his relationships with other characters. For example, he might turn to Neville for support more often. Also, the power dynamic within the wizarding world could shift. Since Ron and Hermione were important figures in the fight against Voldemort, their absence could give the Death Eaters an advantage, or it could inspire others to step up in unexpected ways. Harry would be forced to grow in ways he hadn't before, and it would be a journey full of self - discovery and new challenges.
There's often the sacrifice plotline. They might sacrifice their relationship with Hermione to save a large number of people. For instance, they learn that a dark wizard will spare many lives if they abandon Hermione. Also, the jealousy plotline can exist. If a new character becomes closer to Hermione and they feel left out, they might leave out of jealousy and a sense of not belonging in Hermione's new social circle.
He might cope by focusing on his training. Harry could see it as an opportunity to become stronger without distractions. He would pour all his energy into learning new spells and improving his magical abilities.
One possible reason could be that Ron has deep - seated feelings for Hermione that he's not fully aware of yet. In the story, he might be subconsciously drawn to her and thus won't leave her alone.
One possible story could be that in these 10 months, Ron and Hermione are on a mission together. They face many challenges that test their relationship. Maybe they have to deal with a dark wizard threat and in the process, their bond deepens as they rely on each other's strengths.
I'm not a big fan of such dark fanfictions, but you could try looking on fanfiction.net. They have a large collection of Harry Potter fanfictions, and you might be able to find one with that plot there.
The relationship might be full of comical moments. Ron's attempts to stay close to Hermione could result in all sorts of humorous situations, like accidentally ruining her study time or getting in the way of her other plans.