Champions League will be tough for Bodo/Glimt. In my opinion, if they were playing in the Europa League or the Conference League with their current style of play they could have had a real chance of success, but here it looks difficult.
It wouldn’t be entirely accurate to judge their overall level just based on the Sturm Graz match, because Sturm Graz is known as a team that both concedes and scores goals easily. I don’t think Bodø/Glimt will be able to achieve such comfortable victories in the Champions League. Maybe there could be 1–2 matches like that, but not consistently.
These are entirely my own opinions.
With the caliber of clubs that play in the UEFA Champions League, I totally agree with you that the UEFA Champions League will be difficult for Bodø/Glimt, and their chances of making it to the knockout phase are very small. Even though Bodø/Glimt will not make it past the qualifying stage of the UEFA Champions League, it is good they booked a spot in next season's UEFA Champions League competition because they will generate revenue for just playing in the UEFA Champions League.