Spaghetti squash

I have frozen it before and reheated. I think the best trick is to not cook completely. Leave a few minutes left otherwise a little mushy

I'm not sure if this would be feasible for you to do at your work, but I used to bring spaghetti squash to work for lunch a lot and here's what I did to "meal prep it"
Cut the squash in half lengthwise and gut it out like you normally would. I usually eat one half of the squash per meal. Then I would cook it in my microwave in my office - put it on a glass plate gutted side down, cover with Saran Wrap leaving part of it uncovered so the steam can escape. Cook it in 5 minute intervals (usually takes me about 10 minutes to cook it) until it's as tender as you want it and then use a fork to scrape out the "noodles".
My favorite way to top the spaghetti squash was to dice up tomato and onion, sprinkle with salt and pepper and roast in oven until the tomatoes start to blister. The put that in my lunch box to top the squash with. Squash, tomato/onion mix, and then about 1 oz of some cheddar or mozzarella makes for a pretty large and yummy, but still low calorie meal