Yes, I have left stock out overnight most of the year (except not high summer) with no issues - as another poster mentioned, you thoroughly hear it again when cooking your dish.
I rarely bother with celery, but I do freeze chilli's as I only use small amounts at a time. Also blocks of feta gets either diced up and frozen or put in olive oil now that I am solo. And I tend to slice and freeze the half a lemon or lime leftover from a recipe to use in drinks or water as I may be slow to use that up. And I spent an hour last weekend blanching and freezing beans from my plant, and beans I hadn't used as planned from the fridge, as neither would get used this week (home to see family). And I'll use those for dinners in the next few weeks when I am back.
Whereas I've just finished lunch here, that was a chicken and mushroom soup using the ends of a couple of cartons of mushrooms from the fridge, leftovers from last night and chicken stock (the water with salt and pepper from poaching chicken for dd) and a couple of the small tubs of chicken juices from the freezer. DH will eat the leftovers from the freezer but he wouldn't touch the stock in what he cooks, so I'm trying to be sensible for them too.
The one that needs to wait for me another trip is the 200mls of mussel liquor, as that will make a great seafood risotto base but that's definitely something DH won't make but he loves to eat it. Am home again in August...
But for "ingredients ready to use" category, I love to prepare and dice to equal sizes a mix of Mediterranean veggies (onion, garlic, tomatoes, mushrooms, peppers and courgettes mainly), toss in some olive oil, balsamic, salt/pepper, and herbs (thyme, oregano, basil), mix well and freeze in a big ziplock bag. They can be cooked directly from frozen for easy midweek veg when I am already using the oven, leftovers freeze well again as roasted veg to add to tomato sauce for pasta etc or to make an easy ratatouille. And it means if I have misjudged usage, I can freeze veg that is starting to turn rather than wasting it. Or do larger chunks for BBQ's - that I can do the weekend before a gathering when I am not rushing to get things done and be a calm host.