* Weekly meetings (every Wednesday for 1h) where everyone can just share what they're doing in life. Can also be about work, but it's mostly about general life stuff. That is where we connect.
* 1-2 per month we have an educational talk similar like TED talks where we talk about topics like GTD, personal finance, investing, health, hobbies, training, etc.
* 1 time per year we have a mandatory "University" event where we spend a week in a remote location teaching each other mostly technical skills (but can also be management and design skills). All paid.
* 1 time per year we rent a huge house over an extended weekend and fly everyone in. Including partners and children. All paid.
* Multiple times per year we offer skiing, surfing, and hiking trips. We pay for the accommodation. Team members have to pay for their own food and travel expenses.
More details in our company handbook: https://mobilejazz.com/company-handbook-pdf/ (free to download, no email required, just click the download link)
It's probably much cheaper than the yearly cost of having a corporate office.
And if someone cannot attend due to personal reasons he or she would feel left out. You don't want to create a situation where remote workers feel like they absolutely need to attend something in person. That's just the same as going to an office.
I previously worked for a fully remote company for 3 years and we hosted a conference for our customers every year in January in south Florida. The team all came in a few days early, usually brought spouses, kids, and we generally had a great time building social bonds and doing some light planning for the year during those days.
It’s a balance. Remote doesn’t necessarily, and in my opinion shouldn’t, mean never being in the same physical space as coworkers.
I've spent several years traveling, and right now I'm at a point in my career/life where I try to avoid traveling abroad as much as I can. I enjoy having my routine. That was my reason for working remotely in the first place. Of course, everyone has different reasons, and I am sure there are a lot of people who would enjoy such a trip.
I believe there are probably quite a few people like me who don't enjoy traveling, and "celebrating" by forcing those to travel seems unfair. Traveling for business reasons when it's a necessity to meet in person is a different story - I can understand that and I'm willing to do that. Like you said, having some in-person time can be very productive. But it sounded like the OP was looking to give a reward/gift to remote workers - to me traveling would be the opposite.
TLDR; If you want me to travel say it's part of the job to have a once-a-year meeting. That's fine. Don't say it's a "celebration" or "reward" - because to a lot of people it's not