Im very sorry but I think you actions and justifications for those actions are completely in the wrong. I understand that it may be difficult for you to want to curb your dogs natural instinct to bound and run around but you absolutely have to. Your dog is your responsibility and it is unfair and unforgivable to impose this on your neighbours. You may have to keep the dog in the house at times if the alternative is that he pesters your neighbours. I love animals and especially dogs but you have to be a responsible dog owner and that means taking steps to ensure that nobodies peace, harmony or property is disturbed by your dog. A large dog bounding into a garden that is unknown and of unknown temperament to someone, can be scary for most people, even if they are dog lovers. I can only imagine it might be even more frightening for small children or in this case an elderly lady who is blind. When you're a dog owner, you don't just "try your best" or "do what you can" to stop dogs escaping - you absolutely have to make sure they don't. Could you build a higher fence? Can you put the dog in a very long, loose leash?
With regards to the trailer situation, it would be a nuisance to anyone but for someone who is visually impaired, it might make it harder for her to navigate as well as like you said, make things more scarey. But regardless of whether she had an impairment or not, it would be annoying for anyone. Even though you were unaware of your work schedule, could you have moved it the first day you got back from work? Can you leave it for the time being at a friend or family's house who lives nearby before you figure out a permanent place for it?
If I were you, I would move the trailer asap and visit both the neighbours house in a friendly manner and maybe even with a store-bought or baked cake and apologise to neighbour 1 for having kept the trailer there for so long - but it is now moved and reassure her and neighbour no.2 that the dogs will not run into their garden. This does not mean saying you will try your best to make sure it doesn't happen. You have to reassure them that you have or will actively take steps that will cause 0% chance of the dog running into their gardens.
*Sorry, I posted that before I read your clarification. Yes if I were you, I would approach the daycare neighbour and introduce yourself and tell her about how you will contain her dog to keep her mind at peace. Be friendly, take her concerns into consideration and don't be defensive. She's looking after children so even one small dog escape mistake, even if it just happens once, could be very concerning. Parents may be reluctant to leave their kids their if there is a chance a dog might run in (even though i'm sure your dog is lovely). If you legitimately listen to her worries and be friendly and accommodating about being a good neighbour and dog owner, I can't see how the conversation will go anything but well.