I assume we are discussing Modena and not the other sites.
I have done it multiple times including twice on day trips from LHR. With lunch or… in the old main square and a visit to Panini to see the gems there as well –on the same day —it’s a good day out and way to spend a day in ones’ life.
I doubt whether they are  running visits at the moment as MC20 continuous production there stopped many months ago due to low demand.
You can email or ring Maserati in Italy direct and ask . Contact details (email and phone) are on the maserati.com website and they pick up / reply pretty quickly normally.