The United Kingdom has unveiled a COVID Threat Level ("CTL") scale of 1-5 (5 being the highest). The higher the threat level, the more social distancing measures have to be put in place. The Newfoundland & Labrador government has also rolled out the Alert Level System (1-5 scale as well).
It is very likely that a similar system will be used in other parts of the world, as well as understanding internally developed verbiage for Emergency Preparedness at events/functions/gatherings of any size. Live events should be planned for with a similar system in mind throughout the process.
Venue capacities may need to vary on a sliding scale as the regulations put in place by Covid-19 restrictions change constantly. Using a 1000 person event as an example:
CTL 1 - Capacity 1000 100% (little or no distancing guidelines)
CTL 2 - Capacity 750 75%
CTL 3 - Capacity 500 50%
CTL 4 - Capacity 250 25% (highest social distancing mandates in effect)
CTL 5 - Event Postponed/Cancelled
Even if you are planning your next event at CTL 3 - you need to be prepared to slide that scale up or down at moments notice. Figure out where you can stretch budgets, how will you manage/communicate/plan for extra sales becoming available if restrictions loosen, or process refunds if restrictions increase. Keep in mind some contracts with Artists, Sponsors, Venues, Ticketing, etc could be tied to an agreed upon capacity so it isn't as easy as just opening the gates for more sales without much further planning and discussion!
The incentive for people to purchase tickets early would be to lock themselves into the smallest allowed capacities pending the event is a go (CTL 4). Surge pricing for these "tiers" could cause a lot of problems, however, those negotiations may be possible with Artist Fees and a bonus structure based on sales and the threat level. Consider the following:
CTL 1 - Artist Guarantee 100%
CTL 2 - Artist Guarantee 75% + bonus (calculated on back end event profit)
CTL 3 - Artist Guarantee 50% + bonus
CTL 4 - Artist Guarantee 25% + bonus
A good relationship with Artists, Management & Agents will be imperative to be able to even start these negotiations, but pending how long certain restrictions are in place Artists will need to be getting back to work just as much as events will need to continue to go on! Just some food for thought on how to think about your event budgets in creative ways to make it profitable for everyone involved.