Your success in regaining your ability to move after LL mainly depends on how much effort you put to improve your elongated and deformed muscles.
If you see intensive physiotherapy treatment and do exercises on your own too, there is no reason you lose range of movement in your joints. It is really painful at times (for example, when trying to extend your knees fully), but you will see improvement in range of motion as much as you force it.
5 cm is a good amount to lengthen with minimal possible issues. Your muscles will not be subject to too much tension and you will return to your normal life faster.
What basically happens in your leg while doing LL: You lengthen the bone, and in theory you can do it endlessly. But the surrounding muscles, nerves, blood vessels will limit it, they cannot be cut and lengthened the way you do it with bones. In reasonable amounts of lengthening, the deformation to soft tissues is minimal and muscles can be trained to their new length. 5-6 cm is less trouble for soft tissues than 7-8 cm. More than 7-8 is possible only in some patients, who initially have more soft tissue flexibility. 8+ cm can be dangerous as you might have permanent problems.
Have a good day and hope you get your dream height!