Just received FULL refunds for both the flight (United attempted to shift my departure forward by a full day), and the hotel (which updated its cancellation policy to waive fees b/c of COVID-19).
This despite an email from the hotel last week requesting I reschedule due to 14-day quarantines for arriving travelers through the end of June...
But vouchers only give you a future credit for UP TO the cost of your existing ticket.
Future flight costs more? You pay the difference.
Less? Airline keeps it.
Be firm, patient, and know the rules. The rest should take care of itself.