My friend is coming to Helsinki on the 20th of May and we have accommodation until the 31st of May, after which we will be flying out to travel central/southern Europe.
My question is whether 10 or so days is enough time to comfortably show him a bit of Tallinn, St Petersburg and Riga, but also Lapland for a bit (early midnight sun), whilst still experiencing Helsinki enough?
If not, would it be a better experience to show him around Helsinki more and ditch Estonia, St Petersburg and Latvia trip for Lapland?
We only have until the 31st

Thanks!!