Time machine time capsule at night

to avoid wifi drain

The best way to avoid punishing your Wi-Fi performance is to not have much to Backup at any one time, and to do it slowly, in the background, at low priority while you continue to work.

That is the way Time Machine does its business.

Except for the first Backup, Time Machine does incremental Backups, only saving what has recently changed, not everything. It depends on what is already saved as a base. There is no need to leave its backup until midnight, because it only does a modest amount at a time, and does so slowly.

Time Machine is not the best Backup utility for all situations. But it is the Backup that gets done, because it does NOT wait later, it just plods along in the Background.

In a very quiet way, Time Machine is another feature that lives up to the label, "insanely great!".

When I first looked into Time Machine, the first thing I wanted was a way to delay its backups to occur less frequently. Like you, I wanted to be sure that backups did not interfere with foreground work I wanted to get done, and I was backing up everything from every Mac in the house all at once.

Once I found that there was A way (any way) to reschedule its backups to more convenient times, I proceeded to turn Time Machine on anyway, figuring I could use those other techniques later, when its performance proved too intrusive.

It never proved too intrusive. I never looked further into rescheduling. For me, Time Machine lives up to its hype.

As I said above, the one exception is your initial backup. For that, it may pay to take your most active machine and hook it up by Ethernet cable until the initial Backup completes, just to save time. After that, I expect you will find, as I did, "It just works".