Having had experience in a law office that did foreclosures, IMHO the virus isn't likely to affect the actual housing
market as much as it will affect the time it takes to get paperwork and research done. All types of offices are likely to be short-staffed in the near future unless there is provision for them to work from home. And if in-person document searches need to be done (out in Riverhead, for example), if the County offices end up restricting hours and personnel, it will make things take longer there also. So instead of things moving at the normal snail's pace, it could be more sloth-like.
And then when things do start to "normalize" again, there will be an even bigger and longer backlog than usual.
Depending on the exact nature of the title problem, IMHO the timeframe you were originally given is probably realistic for pre-Covid days.
One thing I do see happening in the market is that realtors will probably cut back on or eliminate open houses. Maybe Tom and Elke would like to chime in with their thoughts on that?
If you are asking whether more houses in Manhasset Hills may come on the market as the result of changes to the workplace due to the virus, honestly I don't think so. Most people who live there aren't living month to month. The lower-level Northwell employees such as maintenance staff aren't living in Manhasset Hills, and the higher-ups and medical professionals who do live there are probably in better shape financially to weather the current situation than most.
I would think that the trades you will eventually want to employ for renovations are more likely to be impacted by the economic effects of Covid, than anyone who lives in that area. Home improvement contractors are likely to see fewer jobs overall because middle and upper middle income people will be less likely to spend money while this is going on. No doubt some of the smaller contractors may have trouble weathering this, or at the very least may need to let some of their crew go because of either illness or lack of work/income; the question then becomes whether they can get those same people back when things turn around. So you might not be able to do some renovations as quickly as you might like, if/when the time comes.
ETA: Out of curiosity I just checked the Suffolk County clerk's web site and they are already restricting access to County buildings. Nassau County already closed the Clerk's office once already (yesterday) and it's likely there will be other restrictions in place as time goes on. So things are already slowing down in regards to anything that needs to be done in person or by bureaucratic staff.