Seed potatoes by the time you get them from your supplier have a chronological age and a physiological age. Depending on how well it has been kept by the supplier, its physiological age may be older then its chronological age would suggest. Factors that increase physiological age include crop stress ( high temperatures, low moisture, frost damage, disease ), damage from handling, and high storage temperature. A seed potato that has been purchased still dormant will last longer.
One of the best-known potatoes for storage is Russet Burbank because it has a long dormancy period. The longest period observed for this potato variety over an observation period from 1999-2013 is 200 days at 42 deg F. Storing potatoes at lower temperatures causes sugar formation which is generally undesirable when used for consumption. Herbicides are misted onto potatoes for sale as produce to inhibit sprouting, and commonly chlorpropham is used. This may well affect the viability of seed potatoes, and there are alternatives such as ethylene and essential oils which can inhibit sprouting for a few weeks without affecting viability.
However, the problem is that unlike a seed which is largely metabolically inactive, a seed potato is actively respiring and physiologically ageing. This will eventually trigger the physiological processes that cause sprouting, and measures to try and stop this may well affect the viability for its use as seed. Since you've already ordered tubers as seed, the approximate maximum duration you can keep them as seed before they break dormancy is 200 days but will depend on what variety you ordered and you might be able to extend that for a few weeks without affecting viability using seed inhibitors.
BTW, if you're interested in developing or keeping potato varieties, you can check out the Kenosha Potato Group on facebook, with over 2000 members, and the Seed Savers Project
Edit: I purchased .6 mm mesh last year to protect against the potato tomato psyllid, and it's also has been found to protect against potato blight (Phytophthora infestans) in one part of this country. So, you could consider using this to see if it protects your crop.