Too long for a 7 year old?

[SummerHolsNearlyHere]

NCed for this, as don't want it linked to other posts. Changed a couple of details, as people I know are on MN.
So, this Summer's plan has been for my DC aged 7 and 8 to spend some time with their father (my ex) in his European country with his side of the family.
Really pleased for my DC to have this opportunity, as they haven't seen their European family for knocking on 3 years.
My parents are dead and I don't see my sibling, so it's great he has such a large, close-knit family.
Originally agreed on 10-12 days. Felt this was long enough, as they see him one weekend a month, when he travels to our area of England to see them.
For context, both have mild to moderate SEN.
He texted me this morning to say he is booking tickets this week and gave me new dates, which mean he 'intends' to take them for 3 weeks.
I haven't replied yet.
I think it's too long.
They've never been with him that long (maximum was 10 days 3 years ago, during which time I had major surgery, so it was a blessing they were away).
On the plus side, I trust his female relatives and know they would love and look after DC (my ex doesn't really parent: he's just fun/permissive/not really the best role model) and I'm sure it will mainly be amazing for DC.
However, with SEN in the mix - and them being around family who really don't know them - AIBU to think 3 weeks is too long.
(And, yes, selfishly, I'll miss them and don't want them away for half the holidays).

AIBU - 3 weeks is fine
AINBU - Stick to around 2 weeks

He’s their parent too.

Yep, wasn't questioning his paternity!
Just gathering views from others with the given context of him only seeing them 1 weekend a month.
But, most people seem to think 3 weeks is okay, so we'll likely proceed with that.

Then SEN, it sounds like, will make problems more likely but not inevitable, so having a back up plan should ameliorate that concern reasonably well.

However, given everything you say about the extent to which you have to facilitate your ex’s contact - generally and for this holiday (the spending & food money and, it sounds like, having a resourced back up plan) - you would not be unreasonable to insist on the original time frame.

But if you want your DC to have the best relationship with his family they stand the best chance of that from the longer time with them. I don’t think that has to be your priority, but if it is you should probably let them go with a back up plan in place.

I would feel it too long. It’s a really long time at their ages. 2 weeks max.

just my opinion with an 11 and 13yo asd dd who have not had more than a weekend without me. They struggle with holidays anyway and without mum they would find it so hard, especially the 11yo. Dh and I are together- but they are much more attached to me.

I think it's fine. In the area where I live there are many eastern European families and this scenario is very common. My daughter's best friend is going to spend the entire summer holiday with her father in his home country, and she rarely sees him otherwise. They are 6.

His family don't speak English

Can the kids speak his language?