A Vindale cloak, according to its description, protects you from Etherwind when worn. Experience shows that the Ether Disease can still grow worse, but is greatly delayed - the symptoms show a month or more later.
Given that the cloak does not fully prevent the disease, you should still find shelter as soon as possible. It's generally a good idea to reduce the weight of a vindale cloak and carry it at all times. The weight can be reduced by using material-changing scrolls (inferior, change or superior) to roll light materials like cloth, silk or spirit cloth; scrolls of flying can also help, but they are much harder to find and could be better used on other items.
It's not unique and a common item to wish for; it can also be bought from general vendors, though a high shop rank may be needed for the cloak to appear. Also, while extremely rare, it's possible for NPCs and adventurers to get one in their inventory. In Elona+, it can be crafted with 50 levels in Tailoring.
It is entirely plausible to get a [Great] quality Vindale cloak if you are lucky. Also, while very rare, it is possible to find <Miracle> quality Vindale cloaks as well.
|It weighs n.|
|It modifies DV by x and PV by y.|
|It protects you from Etherwind|
|Note: Attributes will vary depending on the material.|