“The interpretation of deeds in a quiet title dispute is ultimately to be resolved by this court.” Harvey v. Hsu, 144 N.H. 92, 93, 737 A.2d 654 (1999) (quotation omitted). “Our determination of disputed deeds is based on the parties' intentions gleaned from construing the language of the deed from as nearly as possible the position of the parties at the time of the conveyance and in light of surrounding circumstances.”