If you are a Premium member you will be able to claim for alternative accommodation if the sit is cancelled . There are some T&Cs you need to comply with to make a successful claim . We have done this successfully and this thread is helpful .
If you are not a Premium member than you will need to go with your Plan B -
That could be looking for another sit in a different location / country .
For example are several hosts currently looking for sitters listed in U.K. with sits starting this week - so it may be worth exploring the possibility of getting a cheap flight to U.K. and getting a sit there which would be cheaper than 2-$3000 for accommodations.
To apply for another sit you will need to contact THS support so that they can change the end date of the sit that you are on now .