Originally posted by @Austin Chambers:
How long have they been where they currently are? How much time is left in their lease? I typically don't like moving tenants mid lease, especially If they haven't been there very long. However, if they have been there for a few years already, you can definitely have an addendum that you both sign that terminates the current lease. One piece of advice that I would have is to keep the two leases as separate as possible. Make sure you get a new full deposit for the bigger place and don't just "transfer" the deposit over. You can then go through your normal walk-through process and return whats left of the original deposit afterward. Also, make sure that they are paying for both places during the moving days and not occupying 2 places for a week while moving and only paying on one.
They are new tenants, have 6 more months left on the lease. My rational is that it would be easier to rent the lower priced rental because its only $1,000 because in my area those go quickly