Yeah, I have cherished this idea, though many of us don't care of it. However, a Saami person in my Excel-sheet has more probably Finnish ancestors.
I have heard that in Russian researches have found very wide diversity in some Russian I1 samples. If this is true, are those samples belonging to some known haplotype, primarily into Nordvedt's classificarion.
I know, your I-relatives are very close to count the hapltypes of ansetors of I, I1, I2 and the places of their origin.
But thy are, I think, on vacation now, if they don't want to discuss the matter with you.
I know that this isn't easy task and here is no ready answers. Probably this is too small issue to have interest widely in academic world. Dr. Nordwedt has done excellent job, but has, IMO, smaller interest in a haplotype which exist mainly in one country.
For those, who are not familiar with Bothnia-type, some fundamental mutations compared to the other types.
I1-as has
DYS511 - 9
DYS462 - 12
typically DYS439 - 11
I1-bothnia has
DYS511 - 9
DYS462 - 13
typically DYS439 - 10
I1- norse and Un-types
DYS511 - 10
DYS462 - 13
typically DYS439 - 11
The bifurcation between As and other types has been based on SNP-mutation after founding of SNP-cathegory L22+. AS is L22- and the others L22+. This is of cource basics.
The most interesting issue is that on ground of STRs the Bothnia has diverged from As-type BEFORE the mutation DYS511=10 (but after DYS462=13), which leaded to the Norse and other Scandinavian types. So it is justifiable to suppose that the Bothnia rised in a very early stage somewhere near the place where AS-types existed over 3000 years ago.
The bothnia is absolutely detached from all Scandinavian types, but it could be, besides from Danish and German tribes' area, also from Eastern Europe, where seems to be a big variety of I1-haplotypes, especially from ancient Poland with it's diverse populations is worth of noticing. And if it has been in ancient Poland, it could be also in Russia.
edit
As a double check for the early origin of the Bothnia-type Nordwedt found recently a new SNP-mutation, P109, which rised in certan Ultra-Norse types. It confirms that Bothnia, being P109-, is older than those Un-types with P109+, also having DYS511=10 as all Norse types.
This leads us to an interesting view - because P109+ has been dated by N. to be about 3000-4000 years old, the Bothnia is based on an older type, though it in Finland has been dated to be only 2100 years old. We can surely say that 3000-4000 years old "proto-bothnia" must be somewhere if it hasn't died out.