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We ask for 4 WFC3 orbits to observe the subluminous 1991bg-like Type Ia supernova (SN Ia) SN 2021qvv when it is 150-250 days past maximum light. With observations in F125W (J) comma F160W (H) comma and F350LP (optical) in each of four visits comma we will determine whether this SN Ia subtype undergoes a similar near-infrared (NIR) plateau as the one recently discovered in so-called d_commanormald_comma SNe Ia. The latter have long been used as standard candles in cosmology comma yet the nature of their progenitors and explosion mechanism remains elusive. The abundance of SN Ia subtypes comma including 1991bg-like SNe Ia comma only complicates matters. It is still unclear whether several (or all) SN Ia subtypes share the same progenitor and explosion method as normal SNe Ia comma or whether each subtype originates in a different type of star and explosion physics. The first option ties into the nagging question of how standard SNe Ia really are as standard candles. Revealing the progenitors of normal SNe Ia and the other SN Ia subtypes would go some way to answering this question. The recently discovered NIR plateau at 150-500 days offers a new way to constrain the progenitors and explosion physics. In normal SNe Ia comma this plateau could be a third NIR maximum comma similar to the second NIR maximum seen shortly after the first peak. These additional peaks could be due to the recombination of iron in the expanding ejecta. These secondary NIR peaks are not seen in 1991bg-like SNe Ia comma a fact used to constrain the mass comma temperature comma and chemical composition of the progenitor. The presence or absence of the late-time NIR plateau in 1991bg-like SNe would place further constraints on the progenitor and the recombination wave model.