The best way to avoid unexpected financial pressure due to changes, cancellations or COVID complications is to buy travel insurance.
Insurance is not included in your budget, but we do recommend purchasing some. For UK Explorers we recommend using Coverwise: https://www.coverwise.co.uk/ or, for US Explorers we'd recommend using World Nomads: https://www.worldnomads.com/row/travel-insurance.
In most cases, you can buy worldwide coverage. However, Journee will tell you the correct geographic area to purchase when necessary, all you have to do is ask!