It will be really difficult to make that specific tile into a large and seamless big auto-tile because of the diagonal highlights (due to the ice being reflective). There is only limited space in auto-tile and it has to be created in a very specific way -- all of which makes it difficult to do things like highlights and have them come out right.
One option is to not include the highlight into the auto-tile at all. The problem with that option is that it doesn't look realistic. It basically ends up looking like a flat blue/white thing rather than the ice it's supposed to be. You could try to add some highlights on a different layer. But if you go the route of having the auto-tile be a flat color and add highlights via a B tile, it can add a lot of extra work. Not to mention that it removes one of your mapping layers.
Another option (and this might be an easier one) is to go with what RPXP did for ice and make it fragmented:
In this case, it would tile much like a ground with pebbles or stones would tile. But it wouldn't give you the same sleek ice look.
Lastly, you have the option of recoloring/adjusting a water tile to look more frosty. This can give you a quick auto-tile that's also tied to the general look of your maps. If you only use one frame, it will look like the water is still (i.e. frozen). The problem with this is that it might confuse the player if the difference between icy tile and regular water tile isn't big enough. and it doesn't give you a unique "ice" look.
Just my 2 cents.
