This is more an extended comment than an answer. The answer right now is simple: you cannot do that and there is no a reasonable date estimation on when you will be able to do the Santiago Trail again.
It's impossible to give you a response for the near future, but it is possible to give you an answer for right now: you can't do the trek.
This starts with the fact that you quite likely can't fly to Spain.
You haven't told us what your route is, but right now all routes are closed. Most areas in Spain are closed (you cannot cross some borders between towns and comunidades and, of course, you cannot cross from Portugal to Spain except with proof that you are doing so for work).
In addition to that, most hostels and hotels along the route are closed or have restrictions. Your best bet could be a tent (also it's safer; you probably don't want to share a room with unfamiliar people who might be carrying the virus).
Anyway, the situation is changing continuously and could change at any moment. Rumors are that a complete lockdown may be enforced in the upcoming weeks. But maybe in 3 or 4 months everything will open up... or not.. you can't make any plan.