I can get away with leaving mine for over a week in summer with no ill effects as they are in/on bark, but yes having a humidity meter is essential as if it drops below 40% I think they will suffer, but my house seems to usually manage 45-60% without much work, just mist the radiators when they are hot usually does the trick,
S
I am by no means an expert but I bought my first vanda this winter and I had it hanging bare root, which made it difficult to water and keep moist enough. So I have it in a vase now, and it seems to be doing quite well.
I soak it for about 15 min every other day and mist the roots on the days I don't water. It just started putting out a couple new roots and a new leaf a couple weeks ago!
Maybe you should give vase culture try, just my