As it's been mentioned here already bread and muffins can take care of a lot of zucchinis and they can stay in the freezer for a couple years. It seems squash could be substituted, but I haven't had any so I can't attest to the taste.
Another way we enjoy squash, zucchini and cucumbers year round is make chips from them. Soak them in your favorite mixture (salt & vinegar, barbeque, etc.) overnight and then stick them in the dehydrator. Pull them out when crisp and seal them in mason jars. You'll have delicious, low calorie snacks for years to come. There should be plenty of information online.
50-140;
20 plants?!? You can keep a small village supplied for a full season. If you have chickens you'll be able to save on feed for a while.
Unrelated, but related because we're talking squash and zucchini ...
How many of you stagger your plantings of squash and zucchini? Around here the borer bug will destroy the plant towards 2/3 of it's life. I wait 3-4 weeks and plant a second crop. That way we can enjoy fresh squash and zucchini for longer and we don't get hammered trying to preserve all of it at once.