During the Clinton administration there were dozens if not hundreds of people subpoenaed to testify in the corruption/ Chinese funny money investigations. Stupid (also complicit?) Republican committees just accepted letters from their lawyers instead of bringing them in and making them say, on camera, over and over again that they plead the Fifth.
I will be very surprised if the Democrats do the same. It’s more likely that they will bring Roger Stone in to a public hearing, after which it will be on the news for days and days and then use these hearings in campaign ads.