Tequila wrote:
Isn't there one near Billund in Denmark?
Certainly is. I have been to both the Billund Legoland and the UK one at Windsor (during the same European trip in 2007). The Billund one (in my opinion) is the best, but the Windsor one is fine and well worth a visit.
My children are not on the spectrum, so I cannot say about its difficulties in that regard. They were OK for me (undiagnosed mature Aspie adult at the time).
One possibility might be to contact the Windsor Legoland and ask them when crowds tend to be at their lowest - eg which days of the week, which times of day, which holidays, etc. Perhaps tell them your child would greatly enjoy Legoland provided they could attend when it was relatively quiet. Hopefully, Legoland would like to boost their customer traffic during those quieter times and wouldn't mind telling you the best times to visit.