@MissEljebel - I think that being aware of your pace is extremely important. Does it take you a few hours or a few days per page? With this information, you can know what you can reasonably accomplish in a given month and determine if you need to put them on different updating schedules (eg. comic A 2 - 3 times per week and comic B 2 - 3 times per month, or what have you).
Having a buffer is also super helpful, as @Kann mentioned! Adding to that, I'd consider planning some breaks between release 'blocks' in order to replenish that buffer and to prevent burnout.
To echo @rajillustration - focusing on the main comic as the 'deadline' comic and having the second as a 'soft deadline' project is a good way of giving your readers clear expectations, and can really help with taking pressure off yourself!
Speaking for myself, I am overly organized, so I have the scripts, batches of thumbnails, page goals, and breaks for both comics planned out to help keep things rolling smoothly. 