What I'll do is have the beginners do the 8 mile route, while giving the advanced people the option to make it longer. Any suggestions?
Is that at the fork where you see a view of the desert to the north and a big hill to the northeast? I couldn't find the right way to go from there, maybe the snowbank was hiding the route. Any update on the snow?
Yes, it's that fork. When the snow is gone, it's easy to remember to head right and stay on the paved road. As far as I know, it's probably passable by now. After all, it's been hot the last several days. I'll check today, go for a ride there.
Again, for the more adventurous, you can pick either of two fire roads and ride up to a clearing, then ride (I would probably have to walk) up a doubletrack trail at something like a 20 percent grade to the top of the hill, where it joins up with a fire road you can take north and then west to the paved road, past the part with the snow drift.
The longer routes sort of depend on who wants to keep riding. About a mile into the road, there is a alternate off-road route on your left that has about a quarter mile or so of rolling singletrack which then rejoins the paved road again further on. There are numerous fireroads, including that left turn at the fork you mentioned. There are also fireroads that, as far as I can tell, descend down the east face of the mountain towards Wrightwood. I suppose that one could take one of these fireroads down to the 2 and return to WW. Your house isn't the most difficult one in WW to find, if someone takes this option.
The one caveat anyone with you probably should take to heart is that there are always climbs. This is not a downhiller's dream, that's for sure. And it's been pretty warm, so if they do the climb to the top of TMnt, they might be winded and tired, already.
Let me know when you go, I'd be glad to come with.
Another idea you could try is to park a car at Jackson Lake, ride everyone to Inspiration Point, park, ride to Grassy Hollow and down the fire roads to the lake, and shuttle people back. If they are all into off-road biking, that's a short but fun ride.