Most of the runners won't be trying to tire themselves out by gallivanting through the parks. At least I try not to. Most runners may be at the parks post race(s) if at all. As a rundisney participant the most I have spent at a park during rundisney weekends is one day and sometimes I have done the race and not gone to the parks at all. You should also note that the Wine & Dine half marathon is not the busiest race. Usually has a smaller number of participants than other races.
Since your final park day is the first day of the marathon weekend I wouldn't worry about crowds. Most of the runners arriving at that time will be visiting the expo to pickup their race packets.
About a month before the race weekend the rundisney website posts the course maps. In a couple of weeks you could see if the 5K course map has been posted.
Most of the runners won't be trying to tire themselves out by gallivanting through the parks. At least I try not to. Most runners may be at the parks post race(s) if at all. As a rundisney participant the most I have spent at a park during rundisney weekends is one day and sometimes I have done the race and not gone to the parks at all. You should also note that the Wine & Dine half marathon is not the busiest race. Usually has a smaller number of participants than other races.
Since your final park day is the first day of the marathon weekend I wouldn't worry about crowds. Most of the runners arriving at that time will be visiting the expo to pickup their race packets.