If you move the bridge, you do not have to reinstall the sensors. You can add a second bridge, but they way I’d do that is to move the first bridge and install the second bridge where it used to be. Otherwise you would have to reassign the sensors to the new bridge.
Don’t forget to consider how many walls the signal has to pass through, and how many big metal objects it has to get past (refrigerators, furnaces, duct work, etc). Yes, 50’ is a long way.
Wyze does not currently sell bridges separately, although there is a “maybe-later” wishlist item for it that could use some love: