So my players, being rather clever, figured that they could drop really heavy rocks on the roof of the Garrison and/or stone shape a hole in the ceiling and come in that way instead. Gonna skip the details, but it worked. They have stone shaped their way (with a scroll they bought for the purpose) into Deradnu's room from the roof and that's where we stopped the session.
My question is, does this cause a problem, story-wise or CR-wise? Obviously, the inhabitants are going to come running up the stairs once the alarm gets raised, and Jeslyn and Deradnu are not going to be pleased with a bunch of adventurers melting holes in their walls. The PCs are also still level 3, since there are five of them, so it might be a little overwhelming when every tiefling in the place comes running upstairs. Finally, they're missing almost every opportunity for devotion points.
Should I change anything, or just leave it as is and let the natural defenses of the Garrison handle them? Will it matter if they don't get the devotion points?
Not every "creative" solution to a problem works out well for the party, so if they want to dive in at the end (and probably lose one or two members to the Minotaur there) I would let them.
Also, if they make it to the Wardstone Fragment and hit it with the Rod of Cancellation with enough enemies in range of the blast, they may just cause some mass carnage which could be.....interesting.
I'd roll with it and see what happens. Definitely have the denizens of the lower floors send waves of enemies up to attack the PC's, and if it ends poorly for the party they were the ones that chose that course of action. Also, keep in mind that the opportunity for devotion points extends beyond destroying the Wardstone fragment. Nobody says they have to stop and clean up shrines and whatnot before they finish clearing out the place. They can do it afterward, before they rest for the night after defeating Jeslyn and ascending to Mythic Power.