Also since you're flying in a regular vehicle above the weather, weather related concerns basically disappear. You can build a hanger big enough to house the v

Also since you're flying in a regular vehicle above the weather, weather related concerns basically disappear. You can build a hanger big enough to house the vehicles so if you have a 30 minute good weather opening you can use that to get from the ground to the air above the clouds. And since you're towing with presumably a big airplane you could probably loiter for a few hours (maybe more) which would mean that the 30 minute good weather window doesn't need to be all that precise. Even less so if you're willing to use a tanker to refuel the tow aircraft. Further, since you're flying -- not stationary -- you have a lot of freedom to shift the launch point a bit if your weather window moves too far forwards or backwards. If it's two hours too early you can take off early and fly east. If it's too late you can take off late and fly west. 6x the payload for the same rocket is pretty darn attractive!