

every subscription I’ve had through Apple ends at the end of the billing cycle, not immediately.
and yes if you contact them right away they’ll refund you. had this happen a couple of times when I was a day off on when I thought the subscription was renewing.
this is just personal experience but IIRC I seemed to have much better power consumption with 4G/LTE over anything before. 5G/5G+ is good too but that is likely with recent buildout in my area. Weak signal support I have a hard time gauging as the phone bounces back to LTE where I seem to still have good 5G service.