That's a more difficult one, as we really never got to see the Cavs at full-strength play the Warriors in the Finals to make an accurate assessment of how they'd fair (like we did the year after in Games 1-4). Love wasn't really a factor in the '16 Finals (8 ppg on 36% shooting), so who knows what he could've contributed the year before. Kyrie obviously would've given the Cavs a greater chance, but the pace/style of the series would've been different if both those two played - the Cavs were only in it for the first half because they slowed the pace down and had a stronger defensive unit to keep them in games. Once the Warriors made some adjustments to open up the game, they ran away with it. If two weaker defenders in Love/Kyrie played, the game would've been more open from the very beginning, which would've played into GS' favor.
It's hard to say how that series would've turned out, as we never got to see a full strength Cavs v full strength Warriors for even ONE game in '15 Finals. We got to see it in the '16 Finals tho.