To feed and water 25
trying to keep costs down
As your party spans 3 until late you are going to need some cold food stuffs for during the day and then get the hot stuff out later on about 7.
Your slow cooker needs to be large to feed 25 people.
chilli, rice, grated cheese, Tortilla chips - once ready to serve pop on a table with the slow cooker and spoon so guests can help themselves. Put the sides in large bowls so they can self serve those too. If you don’t have already buy a paper party table cloth (roughly £3 from Asda/sainsburys). You can also buy birthday confetti for a few pound to sprinkle on the table.
I’d buy plastic wine glasses, and plastic bowls for your guests to eat their chilli. Plastic forks too.
When guests arrive have crisps & dips. Cucumber/carrot/pepper sticks also for dipping. Nuts. Warm baguettes x 4 sliced with oil and balsamic vinegar for dipping
people will have had lunch so those few snacks will keep them going until chilli time.
re your booze. Keep checking for the specials online. And buy when they come on.
Also I know you are trying to keep costs down but food and drink for 25 people is going to be expensive
Not sure which part of the country you are in but do consider for example our local Indian does a special for £13, starter, naan, rice, curry, side - in your shoes I’d simply order 10of these and open them all out on the table for guests to help themselves. I’d chop the naans in half. So for £130 you could have that headache removed. There’ll be other restaurants who would be similar.
you could for example ask your local Italian for a large lasagne big dish of pasta, garlic breads etc maybe for £100
Also don’t forget local caterers they might be even cheaper to do you a chili rice etc for £25 people - it removes the stress from you
good luck