The size of the logo is coded into your theme template. You will want to create a custom theme then make changes in the theme.scss file on line 512 (if you already adjusted your theme this line number will be different). You'll want to adjust the 100px limitation.

If you'd like to make additional changes you can go to layout.html line 65 (again this line might be different if you have already adjusted your file) you can adjust the 500px max height and width. You might need to play with the sizes a little before it looks right.

Additionally - there is generally a max-width set in theme.scss but also a max-height set in tablet-and-desktop.scss. Usually increasing the logo requires increasing both. We recommend avoiding setting static width/heights because then it could look strange on mobile, so editing the ‘max’s is the best option.