In your case, the meeting (or avoiding a meeting) is not the final purpose, but only a means to the purpose.
Your correct desired result is:
How can I fulfill my role in the team, without sacrificing my weekends?
And the answer comes rom the science of management. You need to do the following (you might be able to do it by yourself, without the need of your colleagues):
The WBS is mostly about splitting the big work into smaller and smaller units of work, until each unit of work can be "easily" achieved by one person.
The planning is about how and when to do the tasks, and by whom, in order to reach the desired goal.
In your case, you need to find the following:
- which units of work have to be done by yourself;
- who has to finish which units of work, in order for you to be able to do your job;
- who needs the results of your work, in order to be able to do theirs.
Once you have these:
- you let your colleagues work on weekends => they give you work;
- between weekends, you do your things => you give them work.
Once you have done all of the above, you just present the results to your colleagues. If they are reasonable, they will accept it. Alternatively, they might request some adjustments, to the WBS or to the plan - which is quite common. Some "negotiation" will be needed, until things align properly.
If they are unreasonable, then you need to seek the support of an advisor / boss / project coordinator / ... and they will act as a mediator to the problem.
Of course, you will explain to your colleagues that you came up with the above-described system, because although you are busy during the weekends, you still want to fulfill your role in the team and in the project.