You can and should negotiate things such as weekends or actual vacations with OSOs. Maybe you won't feel ready for your wife to spend days at a time with her bf for quite some time. You can't demand anything, but you can certainly request things, baby steps, as you both start this journey.
I would say that, in general, relationships in polyamory don't just jump into long weekends and planned vacations with OSOs right away. I mean, a woman, especially, really has to trust a guy before she even goes on a date with him. Personally, I always meet a guy in public once, if not twice, before inviting him to my home for a few hours. We might then go on in this mode for many months, before we start doing overnights or even think about an actual vacation. (Again, this is just general advice. YMMV.)
Of course, this can vary. If a partner is long distance, you'd be more likely to spend a few days together sooner. (I would recommend a woman get a hotel room instead of going to her new long distance OSO's place for the first time, since if things don't work out, she has a safe comfortable place to be until she goes home.)
However, when my ex-h and I first opened our long term marriage, his gf (a former platonic friend) lived hundreds of miles away. So we worked it out (at first) that he'd drive to her city every 3 weeks for a 3 day trip. (A lot of time was spent on the road.) And we did have 3 kids (ages 9-15), and a lot of pets. So I was without his help with the kids, and the pet care, and all the home, garden and car maintenance he'd normally do on weekends, not to mention I just wouldn't have his companionship.
This did not work out well. He was in NRE, and wining and dining and sexing his gf on romantic dates for days at a time, while I was left with all the mundane household tasks. I didn't have an OSO, nor did I feel we had time for both of us to have partners! Meanwhile his gf was envious I had him with me most of the month. And they were spending unlimited time on the phone, as well.
We could have handled this better, but it was 1999 and we had very few resources for tips on how to do this. I did learn that long-distance relationships are extremely difficult and I prefer to this day to only date local people (less than 30 minutes drive away, ideally).