Technically it can be done, but that doesn’t mean it’s wise because there are two potential problems:
The problem with a list is that it’s just a list. Just because someone is on a list doesn’t mean they’re actually in-market for a mortgage or a home and it also doesn’t mean they are even the type of person that responds to digital advertising or even visits Facebook/Instagram often or at all. Because of this, lists usually don’t perform well or even at all like the way a cold audience on Facebook would. Those audiences work because Facebook is using 1000’s of points of behavioral data to find the people who will respond and are truly interested.. A list would not have anything to do with behavioral data.
When targeting a list, the list should have as much personal contact information as possible, most specifically an email address, full name and a phone number. Facebook needs personal data to match that data to their user profiles. If you don’t have enough, they can’t “Find the person”. To even target a list, it is usually best to have at least 500 people in it and even that is on the extreme small side. You'd be much better off with a list of multiple 1000's if you’re going to even attempt this. If the list doesn't match to several hundred people, Facebook considers the audience too small and will NOT let you run ads to it.