We don’t believe in cancelling trips but we can’t confirm just one person on a trip so we don’t open them up to solo travelers until we have at least two folks confirmed on the trip. We’ve never cancelled a trip due to low numbers (or any other reason), and have run trips with as few as two guests but we can’t do it with one.
Same with discounts, trips that have no one signed up yet may have a discount for a two person minimum. Once some people are signed up, the trip and any discount will be open for solo travelers.