I have a B2B SaaS, so might be able to answer this. I never respond to cold email (probable from years working for agencies), but I do see a lot of SaaS founders start looking for some marketing services, even in this time, but it really does depend on the vertical/industry they service. I've seen some that are doing well right now and some that are not. Going to be tough reaching early stage SaaS as most look for non-paid channels (SEO, cold outreach, etc. ), and then move into social, and then last into paid search.