So I'm from California, FH is from Missouri, we live (and will be married in) Wisconsin. We aren't sending formal STDs, and though it's not likely that my family will make the wedding, I don't want to assume and not invite them. I however don't come from a family who can drop everything and travel on a whim, they need time to save. At what point do I message/call them and say "hey, I'm getting married in May. Formal invites will come later, but I'd really appreciate for you to come so I just wanted to give you plenty of notice."?