Align Bootstrap form input fields across multiple rows inside a modal - css

Question

Specifically, the problems are:
The first row wraps to a second line
The input fields do not line up vertically
It might be possible to use a table, but that might break responsiveness on mobile devices. Is there a clean/elegant way to align these input fields?
https://codepen.io/dtgq/pen/rwQRoK
For posterity, a copy of the HTML on the codepen:
<div class="modal fade" id="fjFilterModal">
<div class="modal-dialog modal-lg">
<div class="modal-content">
<div class="modal-header">
<h5 class="modal-title">Filter</h5>
<button type="button" class="close" data-dismiss="modal">
<span>×</span>
</button>
</div>
<div class="modal-body">
<div class="form-group row">
<label class="col-form-label col-md-2">Cost</label>
<div class=col-md-10>
<div class="form-inline">
<div class="form-group mx-2">
<div class=input-group>
<span class=input-group-addon>$</span>
<input class=form-control name="max_cost-gte" type=number placeholder="Minimum" step=1 min=0>
<span class=input-group-addon>.00</span>
</div>
</div>
to
<div class="form-group mx-2">
<div class=input-group>
<span class=input-group-addon>$</span>
<input class=form-control name="min_cost-lte" type=number placeholder="Maximum" step=1 min=0>
<span class=input-group-addon>.00</span>
</div>
</div>
</div>
</div>
</div>
<div class="form-group row">
<label class="col-form-label col-md-2">Start date</label>
<div class=col-md-10>
<div class="form-inline">
<div class="form-group mx-2">
<input class="form-control" type="date" name="min_date-gte">
</div>
to
<div class="form-group mx-2">
<input class="form-control" type="date" name="min_date-lte">
</div>
</div>
</div>
</div>
<div class="form-group row">
<label class="col-form-label col-md-2">Available units</label>
<div class=col-md-10>
<div class="form-inline">
<div class="form-group mx-2">
<div class=input-group>
<input class=form-control name="sum_vacant-gte" type=number min=0 placeholder="Minimum">
<span class=input-group-addon>units</span>
</div>
</div>
to
<div class="form-group mx-2">
<div class=input-group>
<input class=form-control name="sum_vacant-lte" type=number min=0 placeholder="Maximum">
<span class=input-group-addon>units</span>
</div>
</div>
</div>
</div>
</div>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
<button type="button" class="btn btn-primary">Save changes</button>
</div>
</div>
</div>
</div>
<button type="button" class="btn" data-toggle="modal" data-target="#fjFilterModal">
Filter
</button>