To not want to go on a 'surprise' forced holiday with MIL and 3 Nephews

Bloody hell - all you posters saying 'suck it up', op said she dreads it.

Say no now op, or your feelings will matter not a jot to any of your in-laws forever more.

Or don't, and go on suffering. Your choice, don't think your dh is going to rescue you.

Oh good lord, this does change my opinion somewhat. I was thinking you all had your own space, but clearly not! I wouldn’t want to do that either. Could separate units be a compromise?

It sounds horrendous! You'll just have to be honest and tell her that the two of you don't want to come.
"Treating" someone to something they really don't like isn't kindness. They're her grandchildren not yours, and it's understandable that you're not as enthralled about spending time with kids in a kid-centric place as she is. Don't worry about upsetting her - be honest but polite, and let her enjoy the trip with the others. She isn't entitled to your time.

Float the idea of a less kid destination, a nice city centre where you can do some festive stuff altogether or whatever, then drop out of the more intense bits. Leave your dog so theyre not bothered.
I'm not delighted by kids that aren't mine but do feel my nieces and nephews, including on the IL side, are important and worth my time.

A couple of nights out of 365 in the whole
year to make your partners mother happy doesn’t seem like a particularly big deal. It obviously means a lot to her so unless there is some back story I would suck it up.

You have two choices, I think.

Either be completely upfront and say now "if you are thinking about planning another holiday, can we just say now, up front, that we would rather not be included. It's been great, but we feel it's time to stop"

Or just go for the weekend and suck it up. Maybe take a long weekend off work and arrange to do something else nice in the vicinity, just the two of you, for the Thursday/Friday before or the Monday/Tuesday afterwards.

I agree with this, although I appreciate it probably isn’t what you want to hear.

Your husband says "look, we're bowing out of the annual getaway for the foreseeable. We find it a bit much and look forward to getting together instead at X other times"

If they take offence, so be it.

Some of the responses to these types of things are a bit mad. ‘It’s just a few days suck it up’…

Who on earth realistically goes on holidays they don’t want to go on, with people they don’t want to go with for the benefit of other people, sacrificing precious time and finances? Even if someone else is paying it’s still going to cost a fair whack for travel, food and activities etc. There aren’t enough hours in the day for many people as it is.

Do you all stay in the same house?

No, it's not impossible. You're making it impossible because you just give in to her. She can't ground you or take away your phone, so I don't understand what you're afraid of. We are allowed to say no to things we don't want to do.

If you do bite the bullet then do it now, before she plans it and springs the Christmas 'surprise'. A quiet phone call to her to say ' look MIL we'd rather not do a weekend away next year, it's not really our cup of tea' will give her time to lick her wounds before Christmas comes round.

This.

The kids will one day grow up into adults. I know, shocking.

I'd go, for the sake of family relationships.

You need to let MIL know asap about your own Xmas "plans" and then she won't pay for you to part of this Xmas "surprise"

It must mean a lot to your MIL to have her children and grandchildren all together, even if it's just a couple of days once a year. Unless she's a truly terrible person I'd suck it up and go. Your nephews will get less annoying every year (well they'll get more able to play on their own each year, which is often the same thing).

It's impossible to get out of without telling the truth that you don't want to. But that is an option - depends on how sensitive and grudge holding they are, and whether the relationship is important enough to put up with it.

It doesn't sound like a lot of fun for you and I wouldn't be going.
I would just say "no thank you" and leave it at that

She is borderline obsessed with her grandchildren and will get upset...

Sometimes people will get upset. And then they'll get over it. If you're polite and decline graciously, your mother-in-law's reaction is her responsibility. I think going on this trip for the last five years has earned you a pass. It doesn't seem to me that your mother-in-law even considers what you and your husband may like to do, anyway.

Five years in a row is enough for you to have done your bit. You could have another 30- if you don’t stand up for yourselves now, it’ll get harder and harder.

Can you just tell her not to factor you two in this year because you’d like to go away by yourselves and don’t have the annual leave/finances for two trips?

Taking the long view, I would put up with it for 2 days out of the year to keep the peace. Your choice, of course, OP.

If your DP isn’t willing to say anything to his mum ( red flag alert) then he can go you can stay home - the dog finds it too overwhelming 😉😉