We’ve had a similar issue but the other way round.
We are at my brother’s this year. He and SiL are very much of the belief that children should get no more than 4 presents, the whole “something you want, something you need, something to wear, something to read” ethos, which is fine, but not how we personally work.
He has boys of 8 and 6’ and a girl of 4, my two are 10 and 6.
My kids generally get a good few presents but more fun stuff then practical because I think that when you’re an adult, you’ll get more practical things then you could ever want.
In order to respect their traditions and not make my kids look like spoiled brats, we have brought with us four presents for each, kind of along the lines above, a toy, a book, a game and some clothes.
The rest are in our neighbours house, she’s putting them under the tree for us before we get back on Friday as a ‘surprise, those are from us Santa came here instead’ kind of thing.
Got to my brothers yesterday, it turns out they have been thinking about the idea that kids are only kids for a short time and dropped their 4 presents rule.
My nephews and niece have a HUGE pile under the tree, my kids have 4, 3 of which are not overly exciting.
So now I think we will tell them Santa went to our house instead and hope it doesn’t confuse them too much.
The lesson is always communicate if you think it might be a problem!
Mine will be lucky as they can spread it out a bit but it was a bit of a surprise.