Cavs cannot sign Love next year. They are currently at the cap and that is before Kyrie's extension kicks in next year. The only way they could acquire Love would be thru a trade.
That being said, I don't understand why the Cavs can't wait until December/January to see what they have in Wiggins. Maybe he turns out to be the superstar everyone expects and the Cavs don't feel like they need "another piece" in order to contend for a title. Maybe Anthony Bennett turns a corner and begins to play like he was worthy of the #1 pick, and the Wolves change their mind about not accepting a trade without Wiggins. There is no hurry here no need to make a trade right now. That's the point of the trade deadline!
EDIT: Sorry for stating almost exactly what Unky Buck said below.