I have merlin passes. I know you're not talking about merlin passes just legoland but thought it was worth commenting on why I do.
I don't live near to any theme parks - it's an hour and 20 to the nearest
I pay monthly and that covers us for entry whenever we like. The cost of paying monthly worked out to as if we had visited twice on day tickets or something or possibly 3 times in a year.
Now we go when we want, and if it's a bad day with being really overcrowded or weather turns or rides we want closed - it doesn't bother us. We can leave after an hour and do something else that day
I would download the legoland app and pay attention to the queue times over a few days to get an idea
I enjoy Legoland myself! The model parts are very clever and we've just played find the landmark amongst them not even bothering with ride's before now
Merlin obv you can do this then with any of them plus get free parking and a discount on food/gift shop and I save money by having them despite the expense when it's worked out over a year
If you have anyone with any disability- you'll have to apply but be entitled to a free carer pass and say if you have a child on the spectrum, you'd go free as carer - I believe this is for individual parks as well and also can get ride access passes that cut queues- I'm the disabled person so obv my child can't be my carer but bc I have it - he doesn't queue much (you may not have, just worth saying!)