sounds like you have a great trip planned I'm sitting at my computer green with envy!!!don't know if this helps with you FP+ reservations but for some reason MDE will let me look at MK FP availability for 30 days ahead (I'm not an AP holder) and decided I would scope out availability until its time to book mine!!! and I've found quite a few days where there is still availability for both Anna & Elsa and 7DMT so fingers crossed you should get them!!!!!
so excited for your TR!!!!!!
All park tickets have the availability to choose fastpass+ 30 days in advance. Most day guests don't know that.