Thank you Jim. That's a great idea. The width of the current enclosure is 14 inch. Excluding the right hand side pipe/lines, that leaves the new one with 9 inch. I cannot extend to the left as it already next to a stud. Originally when I was thinking cutting the box in half, I was thinking using this one as it is 8.88 inch wide. https://www.homedepot.com/p/Square-D-QO-100-Amp-8-Space-16-Circuit-Indoor-Flush-Mount-Main-Lug-Load-Center-QO816L100FCP/100148341
Now it looks like I can only use RSCH12L125N on your back sheet as current one has 12 breakers. Is it okay to use this one but with N on UL67 listed? Thx.