My experience is that most glues hold a bond for about 1/3 of the time they claim to.
Not many wearers get a solid 4 week hold.
Most of us like to rebond every 7-14 days max.
Its good to be able to clean the scalp and shave any regrowth.

Personally I would advise to have more than one piece so you can detach & re-attach quickly and do the clean up of the old piece at your leisure.

I would have thought Ultra Hold would probably give one of the longest bonds, but the clean up require specialist products.

All glues act differently on different skin types, so others will probably have other recommendations including long bond tapes.