Like mentioned below my personal opinion is you will need to vacate the property as you do not have any kind of formal lease that would state otherwise.

You could consult with a local real estate attorney and see if there are any other options.

Just make sure on your next lease you sign documents and are aware of all the implications of this new property so you are not in a sticky situation again.

Is there something in your agreement, verbal or otherwise, that the landlord agreed to pay for your moving expenses? If no such agreement exists, I can't imagine how a landlord could be forced to pay for you to move out, particularly since you don't have a lease, and by implication, you are on a month-to-month lease whereby so many days notice to vacate may be sufficient.

If the property is sold, and the owner wants the property delivered vacant, the current owner should give you notice to vacate (depending on your state and how love you've lived there, it could be 30 days notice). If the sale closes while you're still there, then it's up to the new owner to give you notice.