In your case, a 7.0 site will be the closest to the look you have now, here are my suggestions:
https://wexley-demo.squarespace.com/ the gallery grid can be arranged in a number of different ways this is one I built. https://christinegregoryphotography.com/ This site has a landing page.
https://avenue-demo.squarespace.com/ is also a good design for photographers/videographers, and bloggers like myself here: my random views I am also using a landing page template, separate from the site template, as the home page, something only 7.0 has without having to code a page to make it.
https://wells-demo.squarespace.com/ has a classic look for photographers and artists.
https://flatiron-demo.squarespace.com/ very good-looking template, with full-page galleries, and no footer.
https://carson-demo.squarespace.com/ keeps the basic gallery structure, but if you want to go big and bold with your portfolio this is the template to use.
All have the traditional gallery look, as opposed to scrolling sections. Everything looks very much the same on mobile but why not have something classic and a bit unique on the desktop? That is where photographs should be viewed most often in my opinion.
