@kcfc, sorry to hear of your cancellation. We have experienced two sit cancellations of international housesits by Pet Parents on first day of housesit. One of these was eligible for THS Sit Cancellation Insurance.
First, if you’ve not already done so then read the policy terms and coverage (link below).
Second, THS insurance covers cancellation within 14 days of start date. So you’re eligible. Hence THS positive response.
Third, THS insurance does not cover travel costs. Or any other cost other than alternative accommodation. As such, THS insurance will not cover reimbursement of your flights.
Fourth, THS policy terms relate to alternative accommodation that is within 20 miles of pet parent location. So if you sought to claim THS insurance for alternative accommodation in your home country then claim would probably be denied.
Fifth, Sit Cancellation Insurance terms and coverage appears quite often on THS Forum. There are many threads (few below).
Sixth, while current policy is better than nothing, we would heartily encourage THS to upgrade the coverage terms. Increase accommodation daily rate and total max claim amount (inflation); extend cancellation period; remove geographic limitation on alternative accommodation; and consider multi-tier coverage for short vs long duration; and/or international location (e.g. travel).
Seventh, life happens. While we have enhanced our due diligence process to expressly seek pet parents that are committed to their intended travel then we accept that stuff happens in everyones lives. So either book refundable travel or self-insure to cover adhoc issues.
Finally, in regards pay first and then claim then suggest ensure THS agree Sit Cancellation Insurance policy applies; ensure new costs (e.g. alternative accommodation) satisfy coverage terms, and check with THS MS as appropriate; then go for it. We submitted claim shortly after incurring alternative accommodation expenses and repayment occurred within five weeks. Some housesitters have had repayments sooner.
Good luck!