Tiara Yachts are built in Holland Michigan. Lots of retired talent in that area. Holland Marine boatyard might be a possibility for structural work. Northport, Michigan has a very competent repair cadre, but it's in a high dollar area with virtually no slips. Irish in Charlevoix is a full service operation. So is Sengs Marine in Manistee, Michigan. Another good bet would be Bay Marine in Sturgeon Bay, Wisconsin. Very experienced with larger boat repairs and there are multiple marina options in Sturgeon Bay. Not inexpensive, but then no place on Lake Michigan is a low cost option when it comes to slips. That said, boat size makes a difference. Smaller is easier.
What size boat and what sort of repair? Are you wanting to just leave the boat at the repair facility and then take it somewhere else for a "seasonal" summer slip....or put it in the water and take off cruising for the summer? Makes a difference because some places have multiyear waiting lists for a permanent summer (seasonal) slip. Big repair places like Muskegan or Sturgeon Bay and maybe Sengs can probably accommodate you with a slip after the repair is finished.