We fight the same battle. We use a regular plow truck to get as much of the snow off as possible, then a tractor with a bucket to dump the snow in an area where it won't run onto the track when it melts. Very time consuming. We drag it with a diamond drag to work the residual snow in with the limestone and try to get some kind of a cushion. I sometimes have to go 30 miles around the track to make it joggable. Like OGM said we also have some cobbled up pieces of harrows etc to drag.
I'll try to describe what we use as a "float". 8 foot wide by about 4 foot front to back. A series of heavy round steel bars about 2 inches in diameter, running the 8 foot dimension, are spaced about 10 inches apart. We hook a chain to the front 2 corners, pile on old tires for weight and hook that behind the diamond drag when e want to flatten out the ridges. We use in the summer, too, to smooth the track, does a nice job of getting out the hoofprints.
The best thing is a real track conditioner. When I grow up I want to get one
The most frustrating part about winter is doing the right thing at the right time. If the track is too soft and thawed, the diamond drag creates little balls that freeze. It really is an art to learn what to do and when. Get some sun even though it's below freezing and the track falls apart. We get little windows to get the horses out. Go out before 11 and you're jogging on concrete. After 1 it's soup. Drag it again when it just starts to firm up enough (9 or 10 at night) but don't put it off til morning or it's rock solid. Drives me crazy.
One thing we do every summer is get a regular road grader to level it off. We bring in 4 or 5 loads of limestone and the whole thing costs about 2 grand, but it's worth it to get rid of the roller coaster.
I have a buddy who is friends with his township road commissioner, and the guy runs over his track whenever he needs it, even in the winter. I'm not that fortunate, my guy is not into horses at all.