This is where, for me, the amount of effort to try to minimize the per meal cost begins to falter.
My "ok, this is how I do it" is to have two different prepared meal services (one microwave, one conventional) that gets to about $25/day for three meals (my breakfast is cheap). This does have a higher cost, but makes up for it with variety that I otherwise wouldn't have combined with portions that are appropriate and no food waste. The corresponding time savings (about 5 min of prep per day) is also a consideration for me.
While I've got space (and a chest freezer), many single people who are living in apartments have more difficulty with trying to buy larger amounts and limited freezer space.
As an aside, I tend to cook more (slow cooker and a stew that is ~3 meals worth - dinner one day and lunch and dinner the following) in the winter. It may be my appetite preferences or the "I don't want something cooking in the summer", but that's just how my meal preferences tend.
3rd party vac bags are inexpensive on amazon
For thawing, I throw the frozen vac-pack into a sous vide set for 0C/32F - the circulation thaws very quickly. Rarely cook in the sous vide much anymore, it's become my thawing machine
For things like carrots, I freeze them in vac bag in an orientation where I can remove just a couple of carrots and then have enough space to reseal the bag in the vacuum sealer to save on plastic waste