Sean about your removed 5/26/22 video.

[Waterman]

Have the power company turn off the service, not the way I had to do things when I worked for the State.😬 I had to work the 480V 3phase circuits hot. Not for the faint of heart when the breakers you are working with are 800 and 1200 Amp 3 phase. With those size circuits, we used insulated "bugs" for making connections and if need be, extending the cables.
You can use a Morris connector. Not cheap but does what you want. Works with size #14 to size #2 wire. Jackson Electric Supply has them. https://www.jacksonelectricsupply.com/Morris-97017-Black-Insulated-In-Line-Splice-2-Set-p/97017.htm  

[Waterman]

Also you can use https://www.homedepot.com/p/AlumiConn-2-Port-Al-Cu-Wire-Connector-10-Pack-95015/204958912

which are a lot cheaper if you can do a side by side instead of inline splice.

[Sean Genetry Solar]

I ended up ordering a 125 amp service panel. I am going to for now move only the circuits that will reach and that way I dont have to extend anything.

My plans are now to have 4 inverters on the wall each with a 100 amp service. That will allow me to use both 200 amp grid inputs. From what I can tell only a few circuits will need to be extended. The goal is to have a 25 percent balance on each unit so that they do not see at or near red line ever. For example my 4 ton air unit will be the only 240 circuit on the panel along with some other rooms in the house knowing that it will be balanced. My Cooktop on another, ovens on another, etc. 

The electric company will not come out unless there is an emergency or a qualified electrician is performing service.