Really great suggestions above and awesome that you are asking these questions. One of the key themes in the above is getting a dialogue going with your staff. Prioritizing 2-way conversations is super important and it is proven to raise engagement. One way dialogues (e.g. email update on the business) are good starts but alone won’t be sufficient if it is going to be some time before you open.
If you are struggling with what to say or do feel free to just ask a few simple questions of your staff:
What do you want to know about?
How would you like to know about it? (e.g. Snapchat, Whatsapp groups, etc)
How often would you like to know?
If you have email addresses for everyone you can create a simple Google form and send the survey out or provide the link via Text/WhatsApp/etc message for people to click on and answer.
If you don’t want to do a Google form you could do a Houseparty or Zoom discussion and ask folks the same thing almost like a mini-townhall meeting.
From there you might get interesting ideas you can build on.