I feel like I’m on the other side of that “leap” at the moment in my own relationship. After 3 years, we’re having some struggles, and I’m unsure how to talk to him about some of the things that are bothering me.

You’re right, you have two choices. Just remember that there are two sides to every coin.
Now on one hand, you could take the leap and get everything you’ve ever dreamed of, maybe more. Or the “honeymoon-phase” will end/dwindle and you’ll either have to pick up the pieces or hope what you’re left with is strong enough to overcome anything. That’s the position I’m in. I took the leap.

On the other hand, he could move to you, you might have a little less, but be equally as happy as you would have been anywhere. Or it’ll put a strain on the relationship, and he might resent you for having him move.

Whatever you decide, you should decide to try in favor of love. You can always walk away or “come home”, but you’ll never forgive yourself if you don’t take the risk. Opportunity is not a lengthy visitor, and it’ll will forever be the chance that you missed, if you don’t take it.

Despite my own position, I would go with the option to travel to him. A new adventure can make the beginning of something truly remarkable, plus you’ll get to know everything you both have to teach each other.