GLC's suggestion is a sound one. The only times I ever venture on the DC beltway to I-66 is on weekends and right now will all the road work everywhere it just isn't worth the detours, nails in tires, etc.
US-340 from Frederick is a good driving road, four lanes most of the way. The VA-7 across the river is a bit more winds and lights but is not a deal breaker. I-70 to I-81 is simply easy to do. Maybe check your Google Maps traffic and flip the coin. But, I would stay away from the DC beltway and I-66 during the work week, even during lighter traffic covid days.