It was announced a few days ago, maybe last week, that Ion Television would be airing Hawaii Five-0 on Friday, January 8 at 9/8c am. I would definitely check that you get the station for where you live as this only applies to those living in the US.
The schedule shows that they will have the first 18 episodes of season 1 from 9/8c am to 2/1c am on January 9.
but if it is too light to see, here it is typed up.
Friday, January 8, 2021 9 | 8 c AM 101: Pilot
10 | 9 c AM 102: Ohana
11 | 10 c AM 103: Malama Ka Aina
12 | 11 c PM 104: Lanakila
1 | 12 c PM 105: Nalowale
2 | 1 c PM 106: Ko'olauloa
3 | 2 c PM 107: Ho'apono
4 | 3 c PM 108: Mana'o
5 | 4 c PM 109: Po'ipu
6 | 5 c PM 110: Heihei
7 | 6 c PM 111: Palekaiko
8 | 7 c PM 112: Hana `a`a Makehewa
9 | 8 c PM 113: Ke Kinohi
10 | 9 c PM 114: He Kane Hewa'ole
11 | 10 c PM 115: Kai E'e
12 | 11 c AM 116: E Malama
1 | 12 c AM 117: Powa Maka Moana
2 | 1 c AM 118: Loa Aloha
I don't know when the rest of season 1 will air or when the rest of the series will air as the schedule currently goes to January 11. I will check sometime next week to see the updated schedule.
If anyone is interested in having a discussion post put up for these 18 episodes, comment here and I'll get something together before January 8.