adjusterjack, your reply wasn't garbage out; it answered my question regarding staying beyond the end of the lease (thank you). I was hoping to tell them 'we're staying put until we can buy the unit' but I do not want to be evicted.
As for my followup question, there was an abortive attempt at buying the condo, with accompanying earnest money put in escrow. That contract has since been cancelled, but the realtor extended escrow so that we can use it for the 2nd attempt at a loan (for which we do NOT have an accepted offer from them, and now it looks like they will change their minds.)
In reply to jk, yes, I think we're out of luck; not only with the lease, but also with the sale.

