Because you said you won't be able to get there the night before, another thing you can do first thing in the morning is use a 'locator' call. When hunting eastern's here in the midwest (i've only hunted Michigan and Indiana with a total kill of 5 birds in about 12 years, so I'm no expert and take this recommendations with a grain of salt) you can use any number of calls early in the morning to try to scope out their position and know which direction to head if you weren't able to put any to bed. They will gobble at an owl call, crow call, or heck, even a car door slamming (wouldn't recommend the last one

). If you have a portable blind (double bull, ameristep, etc.) you could walk around your hunting area trying to locate the birds using your locator call prior to setting up your blind. If you find some birds prior to them flying down you could set up your blind as close as you think you could get without them seeing you and hopefully call them into your set-up.
However, a lot of times the birds already have an idea of where they want to go when they fly down so you may have to just be lucky to have them come your way. If they have a hot hen (or even a cold hen the majority of the time) with them and the hen decides she wants to go the opposite way there is no amount of calling that will bring those tom's your way.
Just keep in mind that if you use the "locate them and then set up your pop-up blind" method you need to make sure they don't see all that commotion setting it up. They may stay in the trees they are in until they are ready to fly down, but they will go the opposite direction when they fly down. Me and a buddy thought we were being super stealthy by sneaking into 30 yards of a group of roosted tom's (without a blind). We were talking with them for almost 15 minutes before they flew down. Well, when they flew down they all flew directly away from us. We thought that since they didn't fly off when we were approaching them that they didn't see us. Well, apparently we thought wrong.
Good luck! It's an addictive experience.