I think the easiest way to fill in the gaps with Luke/Rey will be this:
Opening Crawl scrolls down to >
Villain intro (as in, we learn what the First Order is planning for this movie; could include Kylo, I'm guessing General Hux with Del Toro's character introduction)>
Finn/Poe, supporting cast intro (just a fun adventure scene, maybe just snappy dialogue, maybe an actual action scene) >
Rey's first scene, which is the continuation of Luke/Rey's introduction from TFA. We get to see/hear their first words, and this segues into a bunch of other images, sequences, and Rey wakes up! The "flashback" was actually her having another dream/vision! She is still with Luke, and they have been training for the past year, but her recurring visions of danger and her meeting with Luke have been troubling her for all of that time.
It's an easy way to cover the importance of Luke and Rey's meeting and first conversation, without having to do a direct time skip.