No plans for getting Fastlane
If no Fastlane, Monday will be the day that will be lighter on the crowds (always is OK when school is still in). If the weather is "iffy" it will be even better.
Sunday will be busy...but obviously weather dependent.
The plan of attack is always subjective...although on the Monday you should find the time to get everything done that you want. The only piece of advice that I normally give is that both "Wonder Mountain's Guardian" and "Thunder Run" are popular rides that are NOT on either Fastlane package. As a result the line ups get pretty long for them at any time of day, so these would be the rides to do first, and on the Sunday morning if you are there. They are both located in Wonder Mountain so distance to walk is not an issue. There should be more of a draw towards Yukon Striker (and always Leviathan) so with luck there will be less people going towards the mountain to start the day. Thunder Run is popular because it is a great family coaster but still has a bit of force for the adults!
Apart from that, I hope you have a great trip.