Drew,

Since you say you're running all of this from an add-in rather than the
active workbook, you should probably replace ThisWorkbook with
ActiveWorkbook in the sub.

Sub RestartMe()

strXLfile = ActiveWorkbook.FullName

Set fso = CreateObject("Scripting.FileSystemObject")

strRestarter = fso.GetSpecialFolder(2) & "\restartWkbk.vbs"
Set fileRestart = fso.CreateTextFile(strRestarter)

With fileRestart
.WriteLine "WScript.Sleep 10000"
.WriteLine "Set fso = CreateObject(" & Chr(34) _
& "Scripting.FileSystemObject" & Chr(34) & ")"
.WriteLine "Set objXL = CreateObject(" & Chr(34) _
& "Excel.Application" & Chr(34) & ")"
.WriteLine "objXL.Visible = True"
.WriteLine "objXL.Workbooks.Open(" & Chr(34) _
& strXLfile & Chr(34) & ")"
.WriteLine "fso.DeleteFile " & Chr(34) & strRestarter & Chr(34)
.Close
End With

strCmdRstrt = "WScript.exe " & strRestarter

Shell (strCmdRstrt)

ActiveWorkbook.Save
Application.Quit

Set fso = Nothing

End Sub