Hi @HSD1
What I did was change the variables around until I got what I was looking for, example, this is the code that I ended up using that I felt fit my header perfectly.
I changed “.header__heading-logo {width: 40% !important;}” to 80%
I messed around with the last line turning “0rem” to “-20rem” and it did make some changes but ultimately I put it back to 0.
Additionally I selected a different sized logo and changed the logo size in the “customize” editor.
It’s just a case of playing around with the values and variables and seeing what you like best.
I’m by no means an expert on this by the way so make sure you make a back up of the code your editing or at least make a note of which lines its on so you can revert back.
Also, I’m sure @dmwwebartisan will be able to give you neater more “correct” way of doing it but this is what worked for me. 
@media screen and (min-width: 990px){
.header__heading-logo {width: 80% !important;}
.header {padding-top: 0rem !important;padding-bottom: 0rem !important;}
}