Some slow cooked meals reheat just fine, more so if you have a microwave (which I don't). Soup, for example. Try looking on Pinterest, especially for "dump and go" slow cooker meals (meaning you can pre-prep the ingredients in a freezer bag, perhaps several batches at a time, then defrost & use as needed. Obviously you'd need meat etc that was not previously frozen for this.
I use my slow cooker a lot in winter, it's fab for making a meagre amount of cheap meat - eg cheap end of lamb neck, or beef shin or brisket, go a really long way. Dumplings are good if the soup or stew is on the thin side.
There are loads of "slow cooker" threads on here every winter. Recently:
www.mumsnet.com/Talk/food_and_recipes/2758530-your-absolute-favourite-slow-cooker-recipe
And, my recipes, copied from another thread:
Lamb stew. Very cheap, tasty, dairy free, can be fairly low fat. Does require a certain amount of "hands on" time to pick over the meat.
A piece of lamb (cheap end of neck, whatever), put it in the slow cooker with a very generous amount of water & couple of bayleaves Cook until the lamb is easily falling off the bones. Leave to cool completely . The fat will rise & solidify at the top, skim off with a spatula. Take lamb off the bones & remove any remaining fat. Strain the stock if you want. Put the meat & stock back in the slow cooker, add some soaked, dried beans (I especially like butter beans for this) & pearl barley. Cook until they are nearly done. Add some sliced carrots, potatoes, cook until tender. Maybe add dumplings for the last 30 mins, especially if you need to stretch the recipe to make several meals. Season to taste.
-----
We also like sausage / pork & bean stew. Again, fairly cheap.
If you have time, brown some cubed pork pieces & a diced onion in a pan, or just put them straight into the slow cooker. Add some dried beans (eg cannellini & chickpeas). A tin of tomatoes, & enough water to generously cover. I also add a tin of baked beans - it adds some seasoning & thickens the sauce. Add a bayleaf or your choice of herbs. (I use Savory for this - you can't buy it in the shops but it absolutely grows like a weed in a sunny spot outside.) At some point grill some sausages, then cut up & add into the slow cooker. I find this recipe pretty useful for using up odd bits of winter veg, too.