So much to say.
YANBU. These PILs would drive me nuts.
When you host you should, IMHO, make sure that you have plenty of food to meet the needs of your guests (unless the guests are genuinely the sort of people who will only eat one type of organic bread from Waitrose or think 6 fried eggs, 10 slices of toast, 8 sausages, 6 beef toamtoes (fried), mushrooms and two tins of beans is a normal breakfast.)
IMHO you or DP need to be explicitly clear about what your needs are, and if they are not willing and able to convince you that they will change, or they EVER give you a small meal again, you need to be clear that you cannot spend time being negatively affected. If it suits you to stay in a hotel and meet them for lunch or a day out, or go to their's for two hours between lunch and dinner, then that is what you do. If they have to come to you and stay near yours in a hotel then that is how they will see you.
Not really similar, but I went to a wedding once. I was driving. When I drive I don't like to drink wine or spirits because I find judging to be difficult. I like to have one pint of beer, ASAP after arrival, and then stay off the booze until I leave. At this wedding they were serving champagne after the ceremony, in the bar area. I went to the bar and said "can I have a pint of beer". They refused, saying that beer would not be served until later in the day, it was champagne or nothing. I left the bar, walked back to my car, drove ten minutes up the road, bought a big bottle of beer, drove back to the venue, re-entered, poured it into a glass and had the drink I wanted. I am an adult and if I want a beer in a place that is serving alcohol and does serve beer then I am having a beer.
I don't expect infinite choices or to get exactly what I want every single time. But when I am in a bar I expect them to be able to pour a beer, and when I am being hosted I expect the meals to fill me up.
Zero tolerance of anything else.