Can I fly a STAR (standard terminal arrival route) if I can't maintain the minimum speed for it?
According to the FAA's Instrument Procedures Handbook, chapter 3 (p. 3-16):

Pilots may have noticed that minimum crossing altitudes and airspeed
restrictions appear on some STARs. These expected altitudes and
airspeeds are not part of the clearance until ATC includes them
verbally. A STAR is simply a published routing; it does not have the
force of a clearance until issued specifically by ATC. For example, minimum en route
altitude (MEAs) printed on STARs are not valid unless stated
within an ATC clearance or in cases of lost communication.

So unless ATC explicitly, verbally assigns you a minimum airspeed, you don't have to maintain it. If they do assign one and you can't maintain it, you can simply say &quot;unable&quot; and request to fly it at a lower airspeed. If ATC can't allow that for some reason (like spacing) then they'll likely vector you instead.
That means that if you are simply cleared for the STAR with no specific airspeed it's not a pilot deviation to fly it more slowly than the airspeed on the procedure.
I have no idea how likely or not it is that ATC would allow you to fly the STAR you have in mind. That would depend heavily on traffic, and things could change at any time.