You dont have to keep unlocking the hubs, you can drive in 2wd with the hubs locked it wont damage anything as long as you are not in 4wd at the time.
For reference, you are not in 4 wheel drive if your hubs are locked, four wheel drive is only engaged when you put your little transfer lever into 4H or 4L and your yellow dash light should be on, this will engage auto hubs, but when you go back to 2 wheel drive with that lever the light will go out and you will be out of 4 wheel drive but hubs will still be locked until you reverse, keeping the hubs locked is ok, you are in preparation to use 4 wheel drive again it will not cause any damage just having the hubs locked, so when the conditions improve and you know you wont need 4 wheel drive much or again, you can reverse to unlock the hubs when it is safe to do so, you only need reverse a meter or two.
This is for the A series .
Hope this helps.