Lots of alternatives. Think best to avoid Myrtle Beach area?
Alt #1. Get off I-95S near Lumberton, NC and make our way to Conway, SC via I74 to NC 242 to SC 701/501 to Rt. 17 ( Shortest route by 5 minutes and miles) OR #2. Stay on Route 701 all the way to Georgetown, SC and swing back over to Pawleys Island ( 18 more miles & 20 minutes longer).
Another very plausible route could be to stay on I-95S into South Carolina pass "South of the Border" to Exit 181A - toward Latta/Marion Rt. 38 to US 501S to Conway then to Rt. 17 Surfside (18 miles longer and 5 more minutes) or 701 toward Georgetown. Any thoughts?