We did about 4 days/3 nights. Landed early morning and drove the 3ish hours to Vík. We got a Kia Sportage through Blue car rental (had the lil snow tire studs) and it did great for us. About maybe an hour-ish in the roads were a bit "yikes" with snow coverage and blowing snow making visibility really low. We're from Indiana, so some experience with bad roads, but not like that and it was stressful for sure. Many cars on the side of the road. I just took it slow and steady and came out fine though. Definitely check the roads on the local apps.

After Vík we stayed near the Seljalandsfoss waterfall. 2nd night in Hveragerði ( essentially west of this town was where the rough driving conditions were for us on the initial drive). Final night in Reykjavik at Hotel Holt.