rsvp "likelihood"

The RSVP is the very last step, the one absolutely sure and will not change our mind except for emergencies, answer. So probability should NOT be on it. Since you are planning a destination wedding, you likely are inviting a smaller number of very close people. There is nothing in etiquette that says that at the planning stages, before invitation RSVP you cannot sound people out.
We did not send out save cards, which are a fairly new item. We went the old fashioned route and spread the word, this is when our wedding is, and we will be inviting you and who ever. And we pointed out that since it was a destination wedding, it would help to know about how many were coming , at 3 months out, before invitations. Would they mind if we called? We called all but a former Army CO of FI, and a professor. Very formal people. But we have very big immediate families ( 20 siblings between us, and our parents have 15 sibs and 14 spouses.) Just for starters.
And we were planning a few hours drive for all. With only a 5 month engagement. When we made 110 calls, for 210 potential guests, at 12 weeks out, we got 160 definitely yes, and 32 absolutely not, no reason, or a conflict. And 18 maybes, 8 invitations. Some maybes were, depends on when the baby is born, real last minute stuff. Others, just do not know as kids teams are in a playoff, or BIL getting married but they might postpone, or whatever. So we never sent out invitations to those who said absolutely not. All definitely yes still definitely yes, and every one came. The maybes all answered promptly, one couple depends on baby , 2 declines, Others yes or no on a week. So we were sure of 160 plus 10 WP. 3 months in advance. And of the 18 maybes, 9 accepted, 9 declined by 6 weeks out after having invitations 2 weeks. Our RSVP date was 3 weeks out. Our only change was the 7.5 month pregnant couple whose baby came the day before. I know a lot of people who have done it his. In my area, and far spread friends and family, weddings where everyone travels within the country and Canada, to a point closer to a majority, is very common. Or those from 5-7 European countries will come together. Rather than vacation resorts. But when e eryo e on both sides and friends are traveling, back to when I was a kid and long before Saves were invented, people planning privately talked to or telephoned or sent a letter where no phones. 3-5 months out. And asked, definitely no, maybe yes, definitely, yes. Now and again people cancelled plans and tried something different. Like if all friends declined, though families were coming. Or 70-90% said absolutely no, too far, too costly, date conflict. We were surprised at the number of absolutely yes, about 50 more than we figured. We ended up taking over all but a handful of rooms at a motel resort in walking distance of the Inn which (with a few in own vacation homes) we had thought would house everybody. If like most destination weddings you really are inviting mostly people you are very close to, I would recommend checking no, maybe, yes after Save the Dates. Or doing Save the Dates by phone, so many pop out with stuff, sister's wedding or moving or surgery, that knocks them off early. ... But by the 4 week out or less RSVP date, you want a final, definite with no changes, answer. That is the commitment. Or they should call you, and say what is up, like our pregnant folks, with no other mind changers or no shows.

View Quoted Comment

We sent out save the dates already - now we're just tracking the guests we sent out STD to. However given COVID on top of the destination wedding aspect, the "possible", or "not likely" probability of peoples' RSVP is becoming more common.

I agree with what Judith said.

As you mentioned Caprice, due to COVID-19 things have become difficult to plan and track, however I don't think possible/unlikely/etc responses are something you should do nor rely on - plans change all the time, and the last thing you want is to rely on X people coming who said 'possible' in case things happen which mean they can't attend.

With a destination wedding, I think you just need to be a little more mindful that there will be many more people saying no than what you'd normally expect for a local wedding, usually due to the distance of the wedding and the extra costs involved in attending.

Hi Caprice, this is an interesting idea! I'll definitely pass it along!!