Rifleman Lanny Bassham, 1976 Olympic Gold Medalist, did nothing but dry fire on his way to winning National and World Championships for a two year period circa 1977-78. Yes, pistol has demands different than rifle, but working on the mental game and dry fire execution can take care of the majority of the overall equation for accomplished shooters. Couple that with alternatives like air soft, CO2 pistols, etc, and you have a lot of what’s needed to get through the next few years.
I have enough ammunition to get by for two years at my normal training rate, and can easily stretch that to five years as needed. But “making empties” is a much lower priority for me- dry fire with a laser cartridge has me at a significant percentage of my normal performance. Just being a lot more selective about how I use live ammo now.
I sympathize with those who are just trying to get started now. They won’t have the base built by 50K correctly shot rounds/year for a few years, as I once did. But I see this as an opportunity to create new training methods that can rise to the situations.