If it's getting changed when you get to the garage, the 20/50 will do no harm. Warm it up in the house before you add it and just before you leave. It's a little thick for a cold start and as a semi synthetic, won t offer the same protection to your turbo on a high speed run, but will be fine for a short run to the garage.
I always use a cheap semi synthetic oil for first full on a 're built engine. I run it up to temp and drain it after a short run. It acts as a flush.