If there are no relatives on the ground who speak English and can help, I think the interpreter suggestion is a good one, and I might suggest taking it a step further and hiring an English-speaking tour guide for this.

You can use a site like ToursByLocals. I have no affiliation and no experience with this guide, but here's one in Sapporo whose English seems good.

The benefit here is that you get someone who, as a tour guide, is hopefully likely to be engaging and friendly, which could help to break the ice and keep things from being awkward.

It's an interesting conundrum, and I'm sure that a guide who is interested in bridging Japanese and Western culture could be convinced to be hired to help