We have always used the thicker tea lights as long as I can remember. We light them at 9:30 pm and my team ends up randomly replacing them here and there once a night. We put them out about 8 am. That is a long time burning. In my experience, using a LARGE party cup that is full of sand will take care of any wind problems. Only use the cup to dump the sand in the bag. Place the tea light right in the sand. Make sure the wick is up for easy lighting. I have my younger Girl Scouts take care of the wicks while my older volunteers fill the bags. With about 7000 bags this last year, this works out great. Good Luck!

My Relay used Tealites and the lasted about 7 hours and it was better because the wind had to be very strong for a bag to flame only like 5 did

It sounds like you are referring to the PL Tealights that were donated by the company and the PL team captain.  PL tealights do burn for 6 hours each.  They are not the same as tealights that you buy from the stores in the silver metal cups.  These will last a full 6 hours and I would recommend placing the tealight on the sand exactly as it is.  You don't need to put them into a separate cup because they are already contained in a small, clear plastic cup.  Don't remove them from the plastic container that they are in because they are designed to liquify completely as they burn.  If you take them out of their plastic container, they will not burn properly.  If you have any other questions, please feel free to contact me.

We have used them every year. They may not burn quite as long as votives but they do burn more than 2 hours. They certainly are inexpensive and very easy to use. We just put them down in the sand.

Good luck!