It should've been in the series bible the number of shuttlecraft, crew, torpedoes, etc they had, all of which couldn't be replaced without placing severe restrictions on rations and supplies.
VOY is very much a "bottle show", far more self-contained than any other Trek so errors like these are just all the more obvious.
Commander Austin Harris, First Officer, Deep Space Nine (by FltCpt. Bossco)
8.01 - Darkest Before Dawn
(Chapter 8 added, 12/09/2015)