Hi, Tara.
If I thought the other person was compatible enough, and the situation seemed good for me to live, then I would rent with someone else,
even though it might not be as stable/long-term as I'd prefer.
But at the same time, as soon as I could,
I would locate the nearest Senior Housing rentals, and review them, to see if I thought any would be a good fall-back plan, for later on.
Then I would get on the those wait lists now, just in case I did need it later on.
You could always decide later then, if/when they have an opening to offer you, whether or not, it is a good idea for you to move into any of them.
And if you needed it suddenly or unexpectedly, sooner,
and you were already on their wait list,
then they often move someone up on a wait list, if they are considered in emergency need,
exactly for the reason that you described in this post,
that does happen to people.