You could try an REM suppressor like 5-HTP. For me it suppresses REM for a while, then when it wears off I wake up, usually in 4 or 5 hours, then I can try for a WILD or WBTB, and most of your REM periods will be in the morning, so you may remeber more dreams when you finally awaken in the morning.

Large amounts of B6, like 200mg with food, before bed also usually allows me to awaken some time during the night, and remeber dreams. It works better than 5-HTP for me.

I usually can't awaken in the middle of the night naturally.