Keep in mind that a hippo can outrun a mouse, despite the hippo being big and fat. . . .stride length, much like with Humans and BMR, is a dramatic factor in overall speed.
So a wolf the size of a small pony would likely run a bit faster than your run of the mill real world wolf.
The top 20 list of fastest dog breeds is led by the 40-45mph grehound and whippet, but almost all the other dogs on the list are essentially just large and thus long legged. Goblins are moderately heavy, so I'd assume their riding wolves would be a bit bigger than a Grey Wolf, and thus proportionately faster.
Grey wolves can run at 35mph, and have been observed running 20mph for many hours in a continuous lope chasing down prey.
Greyhound 45mph is 132 feet per round, even assuming that's a Dash, that's a BMR of 26.4.
Wolf 35mph as a dash would give a BMR of 20.5
Wolf 20mph as a continuous run (x2) implies a BMR of 29.3
Scaling up for longer legs might give you more, if you needed them to be faster. . .keep in mind that horses can out sprint wolves, but like human runners, the wolves will run the horse into the ground over the long haul.