Jonathan Keep in mind that my mikei, tenticulata, sibuyanensis are relatively new to me. This will be their first summer here, and my GH has already gotten up to 105 a day or two. That is why I took down two walls so it wouldn't get so hot, but it still gets into the 90's. So far so good. I just have to make them survive for this last summer then I wil give them a true highland environment and I am sure they will do better.
Now my vent 'hotlips' and jungle bells both been through a summer already and both are pitchering like crazy. The jungle bells puts out a new pitcher on every leaf and people have said it is hard. My sanguina has been with me since th ebegining and it just keeps on growing.
I have a ramispina that I had to move inside only because I just repotted it and it didn't like the heat and stress of repotting at the same time. It is doing better now.
So far the main problem I have had is that I repotted the highlanders right before the heat and they cannot take both stressers, but if you have an established plant it might survive a short period, but it will slow down. I have no thoughts of grander that I can keep them at lowland temps all the time. My GH goes into highland mode during the winter with a low temp of about 48, but warms up during the day.
So it is going to be experimentation on your part. I do believe most plant can acclimate to a degree. Look at the windowsill hamata of Jeremiah (I hope that is the right member). But some will not acclimate to the extreme. And then again some will just survive untill more favorable conditions are met. Like my ramispina last year. It slowed down and was putting out smaller leaves during the summer. Then it picked back up in the winter. So you are going to have to just take risks on your own.
Oh I forgot I have a lowii, epiphiata, and lowii x muliensis (spelling may be wrong) that are growing nicely out in the GH and not sure when I got them though. Don't remember if this is their first or second summer. They are both small and the lowii would be putting out its second pitcher if I hadn't broke the tendral of the first one, but lowii is a slow grower anyway. The other two have been putting out pitchers too. The lowwi x mul being the better of the two. They are all growing and getting bigger albeit slow.
So make some choices and see what you can do, just remember you may loose them or have to setup plan two with an indoor growing area.
On one more thing. Both my fuscas I know I had last summer and were doing excellent till I had the hair-brained idea to re-pot the things out of the peat or LFS they were in because of my root rot scare. They got majorly setback because of it.