I don’t have any expert advice to offer you, but I can tell you what my bf and I are doing.
We’ve been dating for almost two years and know we will one day be married. Always having been advised against long engagements, we had decided a few months ago that it would be prudent to wait until there was not much more than 18 mos (or maybe 2 years… still seemed kind of long to us) before we planned on getting married.
Having seen some of his engaged cousins, I know that the first question out of everyone’s mind is “So when’s the big day?” and it seemed, well, exhausting, to have to explain to people that it was somewhere in the not-so-distant future, and that we’re using the time as discernment.
But, especially as we’re feeling called by God to marry sooner (see my other thread, lol!) AND because our ideas about engagement are shifting just a bit… the engagement is probably coming sooner than next winter as we had originally planned.
Our reason is that, really, we’re hitting a wall in our discernment process. Honestly, we have felt engaged in our hearts and minds for awhile now. We need the support of friends and family, and can really only determine exactly when God is calling us to marriage through counseling from a priest and by looking more acutely/realistically at marriage in pre-cana. For us it seems best to get engaged soon, even if that might mean an engagement of over two years. It would be best for our relationship.
That said, don’t take what people on here say about the challenges of chastity during a long engagement lightly! If you’re like us, though, you already are feeling a tug towards desiring the emotional/spiritual/physical intimacy of marriage as you have realized your vocation with one another. It just won’t get easy, even when distracted by wedding/future planning, I’m sure!
So basically, do what is best for your relationship. Do what God is calling you to. No, long engagements are not the best thing in the world… but I really think they’re understandable, especially when one is waiting because of college, and if it’s done for the right reasons.
Best of luck to you, you’re in my prayers!