Another option if it is very early (more than an hour before park opening). Take the MK bus. Tell the driver you have an ADR at CR. He may drop you off right at the CR. Take the boat to WL.
There was even one post where the person told the bus driver (very early in the morning) that they needed to get to the WL. He dropped them off right at the WL. They were the only ones on the bus I believe.
There have been early morning busses for the breakfasts, tours etc. for at least the last 10 years. The MK area busses start before 6:30AM. The busses for the other parks start around 7AM.
There is a bus between WL and MK. Unfortunately, because of construction at the MK bus depot, it soon will be temporarily stopped (untill sometime in January). The bus will go from the WL to the TCC durng this time.
The boat, in the morning, will go from MK to FW first, then the WL, then back to MK. In the afternoon, about 3PM, the route changes - MK,WL,FW,MK.
If you are going after the construction period, the bus to WL will be faster.