It is difficult to follow many of the newer songs in their original keys. I was going to suggest a couple of recent songs, like 10,000 Reasons, and He Knows My Name. We found the go well with small groups, but we have guitar players.
Only if you have to rely on youtube videos or recordings you have to deal with the high ranges of the singers. Sometimes there are different performances in differing keys that might help. Maybe there are performance recordings offered in a key that is easier for the group.