Well it depends where you are in menopause how effective it will be to stay with one part of the HRT or the other for longer than usual.
If you are post-menopausal or nearly so, then as Dana says you can just go with a longer cycle that month and just stay on the oestrogen only part for a little longer. Alternatively depending on when you normally bleed ( ie during the latter part of the progestogen phase or after stopping this and back on the oestrogen only) - you could keep on with the progestogen/combi patches.
If you are still peri-menopausal and your own cycle is pretty regular then you could have breakthrough bleeding with either regime. If this were the case personally I would want to stick with the progestogen combi part of the HRT which should at least limit the bleeding somewhat. If your periods are usually heavy then this is more tricky!
I am not sure you can absolutely guarantee not to bleed at the wrong time without asking your doc for medication for this purpose, but maybe to try to stop your bleed happening at the wrong time if peri, I think, is to go onto the contraceptive pill (and take packs back to back) - or maybe the POP? Sorry I am not familiar with all these options.
Hurdity x