On the verge of being alone for the rest of his life, a lazy man falls in love with a miniature woman who lives in the small model city that he finds in the spare bedroom of his new apartment, but when he can't figure out a way to shrink himself to her size he must push himself to his limits to find a way in, before he loses the girl of his dreams.

First, love the premise

Second, all the elements are there (Assuming that his laziness is what is standing in his way)

Third, this is way too long

I would probably start with,

“When a lonely man falls in love with a miniature woman who he discovers living in a model city in his spare room, He must push past his own procrastination if he is to discover a way for them to be together”

However even that is rough because there should really be something more standing in their way or a deadline of some sort.

I hope this gives you ideas, for the most part you just have to find a way to condense the logline without taking out what makes the story unique.