Can that be done in route?
Well, it can be done at sea assuming you have the tanker and the necessary expertise. Or it can be done in port, which would be pretty obvious. Long and short is that this boat would have needed two or three refuelings on the way there, and two or three on the way back. The question is where, when, and how. And once we solve this problem then we can take up the fact that this kind of submarine has no surface to air missile capability.