James, when you said that Merritt Island is so spread out I thought you might be looking at the whole island. Merritt Island National Wildlife Refuge is located East of Titusville, Exit 220 off I-95. It overlaps some of the northern part of KSC.
Viera Wetlands is located off I-95 at Exit 191 and a visit there is worth considering.
I would suggest trying Black Point first, it is a better road and will let you get the feel of the area. Then go to the Visitor Center and ask what the reports are. The alternative is to drive all the roads a 4-5 hr project at best. Printing out the roads from GoggleEarth or getting a MINWR map is a big help. I believe Shiloh is walk only while under construction.
Yes, Shiloh is still closed to vehicular traffic as of Feb 23. I've left a message with the refuge mgmt asking about the schedule, but no reply so far. Will post if and when I hear something back.
Shiloh Marsh road is reopened after repairs for TS Fay damage. As of April 4, the south entrance off Live Oak Drive is still closed, but the entrance off SR 3 just north of the radar site is open. The road is repaired through to Turnbull Creek at US 1.
We've been up there almost every weekend since Christmas. The last few times, about three weeks ago, it was a wipe out at the NWR. There was NO WATER in the lake areas. Never saw it that dry. Therefore very few birds. They were concentrated at times in some of the remaining small ponds where water was still present. But the best luck was on the Bio Lab Road. There was a very large flock at the south end on the east side of the road, just north of the exit area. Also some of the ponds along the road to the beach. Gators were very plentiful and active the last time we were there. Guesstimate about 30-40 along the road.
The information at the NWR Visitor's center was that the low water level was a temporary condition, due to the tides. But I doubt that it could be down that low for so long. We've pretty much given up on the area for the season and plan to explore other areas for images for a while. However, if anyone is up there shooting and sees the water up and the birds there, let me know! : > )