First, a little history about the forecast icons. The original carterlake script (and the NWS at that time) used fixed JPG 55x58px images in the ./forecast/images directory on their site, and all successor scripts (advforecast2.php both V4.x scraper and V5.x JSON) use the same structure in order to maintain compatibility for updates.
So, your document root (or in your case ./weather-saratoga/ as document root) should have:
./weather-saratoga/forecast/images/*.jpg
./weather-saratoga/forecast/icon-templates/*.png
./weather-saratoga/cache (for storing the cached files)
./weather-saratoga/advforecast2.php (main forecast script)
./weather-saratoga/DualImage.php (to create the dual-image forecast icons)
If your icons are in
./weather-saratoga/saratoga-icons2/forecast/* then they need to be moved up one directory to be in the directories shown.
Now, about the sizes.. the standard .jpg image size is 55x58 or 55x55 (newer NWS icons). I do have a 85x85 set of .png images
available at
https://saratoga-weather.org/saratoga-icons2-png-86x86.zip BUT
they haven't been updated with the new icons that the NWS implemented last year, so use at your own risk. Some folks have opted for the Meteotriviglio animated .GIF icons, and those too have not been updated to handle the new NWS icons introduced last year.
The icons in ./forecast/icon-templates are ONLY used by DualImage.php to construct a dual-image icon when the NWS calls for it in their forecast.
Hope this helps...