Yoga is a solo practice, no matter how many others are in the room. After all, the whole purpose of the practice is 'you' - body, mind, and soul.
Mastering your practice begins with (1) understanding and acknowledging your limitations and strengths, and (2) understanding the foundations of practice following basic laws of nature relating to alignment, balance and movement. There is only one way to move your body properly for a sustainable, therapeutic and progressive practice, regardless of style or lineage.
The foundations of practice include (1) the anatomical position, the universal planes and your axis, (2) understanding the mechanics of movement, and (3) breath control and proper movement.
Once the foundations are established and applied, your focus during practice will turn within. In solo practice you have the freedom to spend as much time as you like on any asana, befriend the wall or chair for modifications, repeat or replace in comfortable room temperature. That is the ideal way to practice.
On the other hand, group practice requires external focus on the words and energy of the instructor, and the pace and mood of the other students. It can be a good experience or not so good. Ideally, your instructor applies the foundations of practice to their teachings and your practice will flourish. In any case, you can discretely apply the foundations to any system or style of practice.
Solo practice, all alone, may seem a little daunting at first, but once you find your focus and a system or method of practice that works for you, it will become the best part of your day when you focus completely within. You will enjoy a flexible, sustainable, therapeutic and challenging, life-long practice. Everything yoga should be.