I keep masdies with RH often dropping more into the 50% region. The key is how you keep the root zone moist and cool. Your temps are higher than mine (although mine sometimes reach that).
I grow veitchianna, baraleana, amabilis (and a couple of others I can't remember now). I grow them in moss in porous clay pots and when RH is likely to be low (most of the summer) I put a porous clay tray underneath with lecca beads, with the pots sitting on top of the lecca and water up to the base of the pot. This keeps them constantly moist because the moisture is transmitted through the porous clay, it also cools the roots because the evaporation from the clay has a cooling effect (really quite noticeable, the pots feel really cold when you pick them up especially on a hot day).
I've not found I have to worry about RH growing in this way, and they cope well with the warmer days as well. Before I started growing this way I had noticeable signs of heat stress on them. Also leaves growing crinkled or not pulling free of the sheath due to low humidity. Only get that now when I've let them dry out. You have to make sure they don't dry out if growing this way because the clay gets hot if it dries.
veitchianna is quite tall although mine is really bushy as well (it wasn't when I got it but has really filled out). It also has very very long flower spikes which either need staking or go everywhere. They are probably about 3 times the length of the leaves at least and last year mine just had flowers showing all over my masdie table where the spikes were laying low among the other plants.
baraleana is more compact, mine is considerably smaller than the veitchianna, and is starting to bush out nicely. It's flowers spikes are relatively long, but hold slightly more upright on their own than the veitchianna. Still probably 3x or more longer than the leaves.
amabilis is also more compact, much smaller leaves than veitchianna and forming a nice compact clump. I don't remember the flower spikes on that to be honest as although it's growing well it's only flowered once for me. I think they are shorter and more upright than veitchianna, but still long compared to the plant.
I have another species I can't remember the name of, but that is tall leaved and not bushy so not what you are looking for, I think my others are all hybrids... just trying to picture the table to remember what I've got