Set default space free in sql log
SQL Server doesn't have this functionality built in, but you could start with this DBA.se question:

Query to report disk space allocation and used space

Then based on the output, grow the log files appropriately.

I'll be honest though: I'm decent with T-SQL, and it'd take me longer to write that than it would to just change the threshold in my monitoring software so that it's more appropriate. Because here's the problem: if you start growing your log files like crazy, next thing you know, your monitoring software is going to be complaining about having less than 40% free space on your drives, hahaha.