Just got back from a recent trip...
Party of 7 in one room 1 in another room
All of our magic bands worked and never went to the front desk. There were no issues at all,
My son has three magic bands; all would open our door and his grandmother's room with no issues.
We switched to another Disney hotel, and there were no issues there. again never had to go to the front desk.
I forgot my magic band and was able to open the door with my phone and the
MDE app... no issue
personally, if you had an old magic band, I would bring it and link it to your MDE app, if not I think a cheap Magic band is 25 dollars, the fancy ones are 45 or 50, I would get a cheap one...